Funny you mention it - I just finished doing up the removable table for my TTT.
Here it is, in place inside the Overlander as it sits at present.
To hold it in place inside or out I used the classic 2-part aluminium extrusion that classic campers used - one part on the table, one on both the outside of the camper and the inside for the enclosed dining area.
I don't have the seller's name handy, but if you do a search of the site for table mounts it should show up (I found it here).
One really neat extensible leg idea I saw here was a crutch - didn't like the aluminium look though. I did mine from an old bentwood maple crutch - a flea-market special at $3/pair.
Stripped the finish, re-stained it to match the interior wood, and fitted it with a pivot/locking mechanism that is no more than some doweling, metal bar and two blocks of hardwood.