Just because XWD isn't an HTML editor doesn't exclude it from ever being able to add HTML tables. Serif's WebPlus isn't an HTML editor either. It has the ability to do tables and generate the HTML for them. It isn't rocket science--it's Xara seeing it as a beneficial addition and to simply do it.

And seeing how the core code is intertwined, XDP would also benefit from being able to create tables from a designer's perspective.