I would not recommend it as they can wobble a bit. Also, unless you attached them to a base plate (which would be attached to the underside of the table) the small bolt at the top of the legs will pull out if the tabletop shifts more than a little. I would instead suggest using lengths of 2x4, which can be cut for you in the lumber department (I have used this service many times!). Even with 2x4 legs, I would recommend 8 legs for a full sheet of plywood: one at each corner and two set in from the long sides and spaced evenly to support the middle of the board. A little more work, but it will be far sturdier.
Ethan, This leg comes with the 5/16-18 hanger bolt. Zachary
I think it was 20 lbs each leg.