The text is a reference to the game show 'Jeopardy!' where contestants choose questions from a board by stating the category and a dollar amount. It does not contain a play on words or exploit different meanings of a word or similar-sounding words. It is a humorous statement because it implies the speaker has unique knowledge, but it is not a pun.
Alex , I ' ll take " Things Only I Know " for $ 1000 , please .