There's a 3/16" lip around the outer edge (as seen on the left hand piece). The three pieces in the centre of the tray can be cut out with a slight edge around the top. The ones around the edge would have that lip on the side - which could serve as an attached sink backsplash I suppose. Or you could cut them out with no lip at all on any of the sides.
The square ones are about 1 3/8" square and 5/8" deep. The long one is 2 3/4" x 1 3/8" x 5/8" deep.
So if you're lucky enough to get chocolates for Valentine's Day, don't forget to check for mini possibilities within the box.