At our quilt Guild in Yuma AZ we use pieces of PVC pipe which we put on our legs of the folding banquet tables. They work excellently and you can have them any length. There is a cap on the ends of the pipe pieces. If your table does not have curved legs I have seen people put a long screw through their table legs to stop the PVC. These are lite weight and gives you what ever height you need and they are relatively cheap.