Here are a couple of pix to better explain side hung drawer runners.
This drawer picture shows the routed groove in the side.
This pic shows the runner already installed in the cabinet side prior to construction. You will notice I made this one with vertically elongated holes for final drawer adjustment after construction, and two counter sunk screw holes that will be drilled, set, and installed to lock the runner in position after the adjustments are made.
The grooves can be easily routed after the drawer construction, your individual tables will dictate how easy it is to install the wooden runners.
Edit to add, Harry's idea of wooden frame members underneath for the drawer to slide on is also an option, depending on your tables construction, you might need kickers above to prevent excessive drawer front drop.