Measure the width of a folding card table, from the widest part of the outside edge to the corresponding point on the opposite side. Do not measure just the top surface, which may be slightly smaller.
Mark a rectangle with this width and twice this length on a piece of laminate countertop. Use masking tape to mark the rectangle. The outside edge of the tape should be along the outside edge of the rectangle. The tape will keep the edge from splitting.
Use a circular saw with a fine blade to cut along the edge of the tape. This is the cutting table top.
Finish the edges of the table top by filing it with a wood file held at a 45-degree angle. File the edge smooth so it will not snag the fabric.
Set up the two folding tables side by side and place the cutting tabletop on top.