Cutting it you want to cut it at a slow speed. Cutting it fast will get it hot and melt and weld back together. As for a 5"hole why not drill a hole and feed your blade through and cut it out. Or go and get one of those cutters that you put in your drill press. Not sure what the name of it is. Wood craft sells them. You can score the plastic on both sides the clamp a 2x4 on top of it and use the edge of the table to snap it off. Just make sure it scored well so it will want to follow the line. Good luck