Odds are the 4 exterior holes were for a C channel The back of the stove may have hooks of a channel hook to lock onto the C-channel. If you have a drop table you may have the same C-channel to hook the table edge to.
Found an exterior picture of a popup with the C-channel. Some also had a leg, similar to the bed legs and a slot screwed to the wall below the C-channel.
Others used the inside table as a cook top hooking it to the C-channel with some kind of support let.