Were you trying to replace the text with a table? Or were you expecting that by selecting the text and taking those actions it would create a table using your text?
I ask because there is no "Convert Text to Table" or vice-versa in RoboHelp HTML.
Helpful and Handy Links
I'm a bit busy at the moment, but I would like to suggest that Mr.
Adobe continue testing this new product.
If you encounter this repeatedly and report it as a bug, then I'm sure Adobe will look at it. However, you stated that this could have been your own fault.
I just repeated the process and RoboHelp did not crash.
Without being able to repeat the crash and not knowing what you did that leads you to think it may have been your fault, there's not much that can be done.
Hopefully this was a one off.
See www.grainge.org for RoboHelp and Authoring tips