principal Hi
Do you mean the Table add-on, right? I can confirm that it lacks of ability to add row/column now. I've reported to our dev team to improve this.
In the mean time, you can edit code of table to add new row/column. I know it's not an ideal way so if you need my help, you can share the credentials of your site and tell me the number of column + row so I will check for you.
Regards