code: public List<MapRow> readUnknownTable(int rowSize, int rowMagicNumber) throws IOException
     {
        TableReader reader = new UnknownTableReader(this, rowSize, rowMagicNumber);
        reader.read();
        return reader.getRows();
     }
docs: Read a nested table whose contents we don't understand.
  
  @param rowSize fixed row size
  @param rowMagicNumber row magic number
  @return table rows