Make collapsible table rows
You can use the nextUntil() jQuery function like this:

(function ($) {
  Drupal.behaviors.collapsibleTable = {
    $('tr.collapsitablesection').toggle(
      function() {
        $(this).nextUntil('tr.collapsitablesection').hide();
      },
      function() {
        $(this).nextUntil('tr.collapsitablesection').show();
      }
    ).click();
  };
})(jQuery);


Put this in the script.js of your theme if it has one, if not add a new one, see the documentation: Using the theme's .info file (Drupal 6 &amp; 7).