Hi Tobias,
I’m seeing this problem on a client’s site. I’ve gone through and turned off plugins to look for conflicts and checked to see if it was the theme that was the issue. I’ve also worked to improve her site speed as well. We’re on v1.12.
In Firefox, I get the error message that “A web page is slowing down your browser. What would you like to do? Stop it. Wait.” In Chrome, it won’t fully load and in Edge it also asks whether I want to stop the page loading.
Not being able to edit the tables is an ENORMOUS issue for this site. Thanks for any help you can give.