A few years back I made something like the card table frame.
3x3 frame with folding legs like a card table. Then made 2 L's from 1x2 wood, (90 degree L bracket) on the inside corner of wood and a L bracket on the ends (bent to a 135 degree )and used bolt with wing nuts to hold open corners together. (Ends sticking out for bolt and wing nuts) The 2 L's formed another square that set around the outside edge of the table. The quilt top is placed on top of the table and inside the L's and wing nuts tightened down. It is really great for tie quilts.
I used it to take to outdoor concerts and quilt while I listened. Small and very portable. At home, when set up, I seem to have a elevated 3x3 cat bed. Have a hard time quilting on it because the cats have to see everything you do and try to help quilt.