Measure the length and width of your coffee table top. Multiply the length and width by four, add together and add 4 inches to determine the amount of 1 x 3" wood you will need for this project.
Cut six pieces of the 1 x 3" wood, using the width measurement of the existing coffee tables.
Cut two pieces of wood using the length measurement, and another two using the length measurement, plus 2 inches.
Set the cut wood aside.
Stack the coffee tables on top of one another. Using your drill, drive a screw through the top of the bottom table, into the center of each leg of the top table.
Nail two of the shorter boards to the upper coffee table, to form a rim. Place nails at each corner, then nails about three inches apart down each of the sides. This will prevent beverages from sliding off the cart. Then, take the two longest boards and nail them to the other side of the top of the cart. The top of your cart should now be fully framed.
Attach the remaining wood about halfway up the legs of the top cart, driving a nail at each end of your wood, through the legs almost at the corner. This will protect items on the lower shelf.
Attach the four wheels, one to each leg of the lower table. Using your drill, screw the caster plate into place, with screws in each corner of the plate.