Now that you've marked the profile for the handles of the tray, the next step is to cut the holes for the handles with a jigsaw.
Using a cordless drill or corded power drill, make a pilot hole in the center of the area to be cut out. Next, use your jigsaw to cut the handle hole. Proceed slowly and let the jigsaw do the work. Cut just up to the line but not over, as you can clean it up in the sanding process later.