Sounds like fun. Will you be teaching all of that, or just the leatherworking?
Do you have a good hammering substrate for the stamps, punches, whatever? If you find the tables have too much bounce, can I suggest what I've seen put to good use at one of the camps I was at? Cheap to make too if they've got a log pile you can raid. The best surface I found at the local camps around here was where someone took sections of log about 2 ft high and over 1 ft in diameter with perpendicular cuts and a level top and bottom. Some logs were bigger, about 2 ft in diameter and nearly 3 ft tall, but these were impossible for one adult to move easily.
They'd debarked the logs and varnished the sides, but the top (cut surface) was raw endgrain wood--as the surface got beat up, they would run a sander across it once or twice a summer to smooth it out again. A metal strap was set into a groove about 6 inches from either end and in the middle to prevent splitting on some, and on all of the logs, they'd secured two thick leather handles to the sides with screws so that the instructor (or two kids) could pick the logs up and bring them into the storage area easily (usually to be laid on their sides and stacked under one of the tables). When in use, the logs were set up on a concrete slab with a short stool the kids could sit on with their legs on either side of the log, or if they were taller, they could kneel or squat, or even sit flat sort of cross legged with the log cradled behind their knees and against their thighs--this was the best way, as the kids were right above their work and their legs held the log steadier. Because the logs were semi portable, they could be moved out to the sun if the light in the huts was too dim (often was) or under a roof or tarped area to one side of the hut if it was raining.