Converts a HTML table with `thead` and `tbody` into an array of objects. You can then use JSON.stringify(json) or copy(json) to your clipboard.

bookmarklet.js

javascript:void%20function(){(function(t){t.extend(t.fn,{tableToJSON:function(){var%20n=this,r=t(%22thead%20th%22,n).map(function(n,r){return%20t(r).text().trim().toLowerCase()});return%20t(%22tbody%20tr%22,n).map(function(n,e){var%20o=t(e),a={};return%20t(%22td%22,o).each(function(n,e){var%20o=r[n];a[o]=t(e).text().trim()}),a}).toArray()}})})(jQuery)}();

table-to-json.js

// Usage: var json = $('table').tableToJSON();
// JSON.stringify(json);
// copy(json);
(function($) {
  $.extend($.fn, {
    tableToJSON: function() {
      var $el = this;
      var attrs = $('thead th', $el).map(function(idx, heading) { 
        return $(heading).text().trim().toLowerCase(); 
      });
      return $('tbody tr', $el).map(function(idx, row) {
        var $row = $(row);
        var obj = {};
        $('td', $row).each(function(idx, col) {
          var attr = attrs[idx];
          obj[attr] = $(col).text().trim();
        });
        return obj;
      }).toArray();
    }
  });
})(jQuery);