Try the TinyMCE demo at https://www.tinymce.com/
Are you able to get tables to operate the way you want them to?
The demo does me no good, in as far as that installation of tinyMCE is not available in WordPress.
As far as the tables go; I went back to using the button and now I can add rows and columns. I can also resize a table vertically, but not horizontally. Not what I’d call a desirable feature.
I asked because that version is available via https://ww.wp.xz.cn/plugins/tinymce-advanced/
Tables are also available through tinyMCE itself. I did try the demo on the tinyMCE site, only to have the same problem there where resizing a table was concerned.
Ok, then what you have is an issue with how TinyMCE is designed to operate, not a WordPress issue.
I recommend sharing your feedback with them at http://community.tinymce.com/forum/
I tried. I asked for a link to reset my password, and got no reply. I have no faith n the people behind tinyMCE.
Ok, well all changes to TinyMCE itself would have to come from them. If you really want to share your feedback, I’d recommend just opening a new account there.
They don’t trust me, I’m not going to trust them.