Q:

Wrapping text in a fixed width table so that table height adjusts

I looked at these questions but they didn't seem to solve my issue because using a parbox for the first column cell doesn't make the table adjust to the content in the first cell, nor does simply specifying the cm width within the multirow option.
\documentclass[12pt]{report}

\usepackage[]{multirow}
\usepackage[autostyle]{csquotes}% This is for quotes
\usepackage{tabulary}% This is for tables
\usepackage{ragged2e}
\usepackage{longtable,array,ragged2e}% This is formatting for long tables
% \newcolumntype{L}[1]{>{\raggedright\arraybackslash}p{#1}}%This is a wrapper to make everything a certain width - http://tex.stackexchange.com/questions/12703/how-to-create-fixed-width-table-columns-with-text-raggedright-centered-raggedlef
\newcolumntype{L}[1]{>{\raggedright\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{R}[1]{>{\raggedleft\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
\usepackage{graphicx}% This is for images
\usepackage{booktabs,dcolumn,caption}
\newcommand{\ra}[1]{\renewcommand{\arraystretch}{#1}}%This is for precision tables per property
% \captionsetup{labelsep=newline,singlelinecheck=false} % optional, this makes the caption numbers appear on a new line.
\newcolumntype{d}[1]{D{.}{.}{#1}} % "decimal" column type
\renewcommand{\ast}{{}^{\textstyle *}} % for raised "asterisks"
\usepackage{bookmark}% This overrides warnings like http://tex.stackexchange.com/questions/52576/difference-between-bookmark-levels-greater-than-one-what-does-this-mean
\begin{document}

\begin{table}[!ht]
\centering
\begin{tabular}{ |C{3.25cm}|C{3.25cm}|C{3.25cm}|C{3.25cm}| }
\hline
\textbf{Sentence} & \textbf{Training Examples} & \textbf{Region} & \textbf{Value} \\ \hline
\multirow{4}{3.25cm}{"Countries with higher GDP per capita at the lower end of the scale include Azerbaijan (around \$7,500) and Botswana (around \$8,900) and as we head up the scale we find South Korea (around \$27,500),the United Kingdom (\$39,600), the United States (\$48,150) and right at the top we find Qatar (\$98,000) and Luxembourg (\$ 122,147)."} & LB & Lucus Radebe & Bla \\
 & DC & Michael Duberry & Bla \\
 & DC & Dominic Matteo & Bla \\
 & RB & Didier Domi  & Bla\\ \hline
\end{tabular}
\end{table} 

\end{document}

A:

\savebox can be really useful in many examples, although sometimes they might be a bit hacky.
This works in the way that it is saving a parbox set to the specified width into a box. We can then calculate the height of that box using \totalheightof{} from calc-package. Then we distribute this length for every row, 4 rows would equal 25% of the height of the box. We then use this length for the linelinespecifier \\[\spacing], but this would overshoot a bit. How much? Well, LaTeX has first added a line in the table, and aftwerwards inserts this length of black space, so we need to take that into account. Therefore, we change the length to \setlength{\customSpacing}{.25\sentenceHeight-\baselineskip}
Further suggestions:

Putiting this much text in a table is not very convinient for your reader. Consider putting that text in a a paragraph for itself, possibly in a caption, or notes below the table. 

Output

Code
\documentclass[12pt]{report}

\usepackage[]{multirow}
\usepackage{ragged2e}
\usepackage{array}%
\usepackage{calc}

\newcolumntype{W}[1]{>{\centering\arraybackslash\hspace{0pt}}p{#1}}

\begin{document}

  \newsavebox{\sentence}
  \savebox{\sentence}{\parbox{3.25cm}{\RaggedRight``Countries with higher GDP per capita at the lower end of the scale include Azerbaijan (around \$7,500) and Botswana (around \$8,900) and as we head up the scale we find South Korea (around \$27,500),the United Kingdom (\$39,600), the United States (\$48,150) and right at the top we find Qatar (\$98,000) and Luxembourg (\$122,147).''}}
  \newlength{\sentenceHeight}
  \setlength{\sentenceHeight}{\totalheightof{\usebox{\sentence}}}

  \begin{table}[!ht]
    \newcommand{\headerFormat}[1]{% Define a headerformat, only used in this specific table.
  \multicolumn{1}{|m{3.25cm}|}{\centering\bfseries#1}
}
    \newlength{\customSpacing}
    \setlength{\customSpacing}{.25\sentenceHeight-\baselineskip}
    \centering
    \begin{tabular}{ *{4}{|W{3.25cm}}| }
      \hline
      \headerFormat{Sentence} & \headerFormat{Training\par Examples} & \headerFormat{Region} & \headerFormat{Value} \\
      \hline
      \multirow{4}{*}{\usebox{\sentence}} & LB & Lucus Radebe & Bla \\[\customSpacing]
      & DC & Michael Duberry & Bla \\[\customSpacing]
      & DC & Dominic Matteo & Bla \\[\customSpacing]
      & RB & Didier Domi  & Bla\\[\customSpacing]
      \hline
    \end{tabular}
  \end{table}

\end{document}

A:

You can solve your problem in two ways:

With multirow, count the number of lines required ((not rows!) and add to the 2nd column a supplementary cell with invisible rule of the required depth (found by trial and errors)
without multirow, make, from the 2nd row, the 2nd to 4th columns a nested tabular inserted in a\multicolumn`.

In both cases I based the definition of L,C,R columntypes on p{…} type, as I supposed the m{…}type was used to have column heads vertically centred, which I obtain with the \thead command, from makecell.
Added:: I also propose a third solution so that rows 2-5 in columns 2-4 be equally spaced.
    \documentclass[12pt]{report}
    \usepackage{xcolor} %
    \usepackage{multirow}
    \usepackage[autostyle]{csquotes}% This is for quotes
    \usepackage{tabulary}% This is for tables
    \usepackage{longtable,array,ragged2e}% This is formatting for long tables
    % \newcolumntype{L}[1]{>{\raggedright\arraybackslash}p{#1}}%This is a wrapper to make everything a certain width - http://tex.stackexchange.com/questions/12703/how-to-create-fixed-width-table-columns-with-text-raggedright-centered-raggedlef
    \newcolumntype{L}[1]{>{\raggedright\arraybackslash\hspace{0pt}}m{#1}}
    \newcolumntype{C}[1]{>{\centering\arraybackslash\hspace{0pt}}p{#1}}
    \newcolumntype{R}[1]{>{\raggedleft\\\arraybackslash\hspace{0pt}}m{#1}}
    \usepackage{graphicx}% This is for images
    \usepackage{booktabs,dcolumn,caption, makecell}
    \newcommand{\ra}[1]{\renewcommand{\arraystretch}{#1}}%This is for precision tables per property
    % \captionsetup{labelsep=newline,singlelinecheck=false} % optional, this makes the caption numbers appear on a new line.
    \newcolumntype{d}[1]{D{.}{.}{#1}} % "decimal" column type
    \renewcommand{\ast}{{}^{\textstyle *}} % for raised "asterisks"
    \usepackage{bookmark}% This overrides warnings like http://tex.stackexchange.com/questions/52576/difference-between-bookmark-levels-greater-than-one-what-does-this-mean
    \renewcommand\theadfont{\normalsize\bfseries}

    \begin{document}

    \begin{table}[!htb]
    \centering
    \begin{tabular}{ |C{3.25cm}|C{3.25cm}|C{3.25cm}|C{3.25cm}| }
    \hline
    \thead{Sentence} & \thead{Training\\ Examples} & \thead{Region} & \thead{Value} \\ \hline
    \multirow{17}{3.25cm}{"Countries with higher GDP per capita at the lower end of the scale include Azerbaijan (around \$\,7,500) and Botswana (around \$\,8,900) and as we head up the scale we find South Korea (around \$\,27,500),the United Kingdom (\$\,39,600), the United States (\$48,150) and right at the top we find Qatar (\$\,98,000) and Luxembourg (\$\,122,147)."}%
     & LB & Lucus Radebe & Bla \rule{0pt}{2.5ex}\\
     & DC & Michael Duberry & Bla \\
     & DC & Dominic Matteo & Bla \\
     & RB & Didier Domi & Bla \\%
      & \rule[-18.5\baselineskip] {0pt}{0pt} & & \\
    \hline
    \end{tabular}
    \end{table}

    \begin{table}[!hb]
    \centering%
    \begin{tabular}{ |C{3.25cm}|C{3.25cm}|C{3.25cm}|C{3.25cm}|}
    \hline
    \thead{Sentence} & \thead{Training\\ Examples} & \thead{Region} & \thead{Value}
    \\ \hline
   \rule{0pt}{2.5ex} {"Countries with higher GDP per capita at the lower end of the scale include Azerbaijan (around \$\,7,500) and Botswana (around \$\,8,900) and as we head up the scale we find South Korea (around \$\,27,500),the United Kingdom (\$\,39,600), the United States (\$\,48,150) and right at the top we find Qatar (\$\,98,000) and Luxembourg (\$\,122,147)."}
     &
     \multicolumn{3}{@{}c|}{\begin{tabular}[t] {C{3.25cm}|C{3.25cm}|C{3.25cm}}
     \rule{0pt}{2.5ex}LB & Lucus Radebe & Bla \\
      DC & Michael Duberry & Bla \\
     DC & Dominic Matteo & Bla \\
     RB & Didier Domi & Bla \\[18.2\baselineskip] & & \end{tabular}}%%
    \\
      \hline
    \end{tabular}
    \end{table}

    \clearpage

    \begin{table}[!htb]
    \centering%
    \begin{tabular}{ |C{3.25cm}|C{3.25cm}|C{3.25cm}|C{3.25cm}|}
    \hline
    \thead{Sentence} & \thead{Training\\ Examples} & \thead{Region} & \thead{Value}
    \\ \hline
  \multirow{17}{\linewidth}{"Countries with higher GDP per capita at the lower end of the scale include Azerbaijan (around \$\,7,500) and Botswana (around \$\,8,900) and as we head up the scale we find South Korea (around \$\,27,500),the United Kingdom (\$\,39,600), the United States (\$\,48,150) and right at the top we find Qatar (\$\,98,000) and Luxembourg (\$\,122,147)."}
     & \rule{0pt}{2.5ex}LB & Lucus Radebe & Bla\\ %
     & \multicolumn{3}{@{}c|}{\setlength\extrarowheight{92pt}\begin{tabular}[t] {C{3.25cm}|C{3.25cm}|C{3.25cm}}%
      DC & Michael Duberry & Bla \\%
     DC & Dominic Matteo & Bla \\%
     RB & Didier Domi & Bla %
     \end{tabular}}%
    \\
      \hline
    \end{tabular}
    \end{table}

     \end{document} 

