Lay the plywood panel flat on a work surface. Draw the outline of the desired recess for the table on to the plywood panel using a straight edge and a pencil. Make the outline 1/2 inch smaller than the desired dimensions for the recess.
Cut out the pencil outline on the plywood using a table saw. Lay the panel flat on the table of the saw and guide it through the saw while following along the pencil line to complete each cut.
Center the cut-out plywood panel over the tabletop. Clamp it down at each corner with bar clamps.
Insert the 1/2-inch straight plunge bit into the plunge router. Lock the bit in place. Adjust the plunge depth on the router to the depth required to cut out the recess from the tabletop.
Turn the router on and position it at one corner of the plywood panel. Plunge the router in a steady downward motion. Rout around the plywood panel in a counter-clockwise motion, once you have reached the full depth on the plunge. Move just fast enough to allow the blade to cut through the wood in the table top. Lift the router up from the plunge position and turn the router off when the cut is completed.
Remove the bar clamps and lift the plywood panel and recess cutout off from the tabletop. Sand the cut edges of the recess with a fine-grit sanding block. Always sand in the same direction as the wood grain.