Hey everyone, I just tested this and neither examples shown here were 100% correct.
I downloaded TinyMCE, put the "table" folder into the plugins directory in wp-includes/js/tinymce/plugins. That part is correct.
Then in the file "tiny_mce_config.php" I edited this line:
$plugins = array( 'safari', 'inlinepopups', 'autosave', 'spellchecker', 'paste', 'wordpress', 'media', 'fullscreen' );
into the array.
I then scrolled down and edited
$mce_buttons_3 = apply_filters('mce_buttons_3', array( ));
$mce_buttons_3 = apply_filters('mce_buttons_3', array('tablecontrols' ));
Then opened up a post/page edit and refreshed the page.... table controls!
But now... what about editing table cell colours? This enables you to edit padding, borders, cellspacing, merging etc. but no colours :(