My portable version......
I've settled on two pieces of half inch glued & screwed together as a good compromise between weight & stiffness.
48" x 30", rounded corners, and a 10" x 16" cutout.
Indoor/outdoor carpet on the top, folded under & stapled.
Folding banquet legs from Menards on the bottom. Off set so the lay flat.
Weight is 37 pounds.
Used to be under $50.00 to build at the old prices.