The xenforo 2 editor is Froala. By default it has a very nice user-friendly and responsive table.
Try it here: https://www.froala.com/wysiwyg-editor
It would be extremely useful to see that implemented in XenForo.
So did Redactor, but both of these are in their standard implementations as HTML editors. Both editors were refractored by the XF Devs to work with BB Code, here they are BB Code editors and tables aren't a default feature. It's something that (hopefully) they will code into their Froala implementation at some point.