I have one of the 6 foot folding tables (Hard Plastic) from Menards and it was too low, so I went down to the local plumbing
store and had them cut me some pvc pipe. Measured about where I wanted it to be and I think I had 6 inch pieces
cut. They cut them all so they were the same length and straight edges and I came home put them on the legs and presto my cutting table is now up where I wanted it to be. An inexpensive solution to my problem, as they cut the pieces from some scrap pieces they had.