Hi Hitch, that's an interesting question! I had thought about it and then decided that I couldn't find a Use Case for it, but then why did I think of it?
Can you explain why you would want to do this?
Technically, there is no reason why you couldn't edit the items from the repeating table AFTER they have been submitted, although probably not in repeating table, off the top of my head the easiest way would be to do it in separate view which retrieves the item from the previously returned record ID and allows the user to edit and save it back to the list via a list data connection.
If there is a need, I'm not promising although, maybe I'll have a go at an elegant solution! :)