Making a table sortable requires lots of additional javascipt, and would need to be a front-end plugin that is activated on specific tables.

This is really out of the scope of JCE's core function as a wysiwyg editor, and is probably best served by an existing extension, if any exist - https://extensions.joomla.org/

That said, if I get some time, I will see if I can knock together a simple plugin for table sorting, using an exsiting javascript library from the web somewhere.