Building a plywood table is not a difficult job. It's cheap, straightforward, and well within your grasp to do at home.
Step 1 - Get the Work Area Ready
Clear off a working area enough to work when cutting the plywood. There will be lots of dust, so use a face mask and keep the area well-ventilated. A work bench will help in setting up the plywood when sawing. When using electric saw, ensure this is safely set aside when not in use and keep loose power cord tucked away.
Step 2 - Cut the Plywood into Parts
Measure 36 inches by 48 inches on plywood for the table top and mark these using a pencil. Cut the plywood using a saw. Measure and then cut 36 inches by four inches on the remaining plywood. Using this as your template, draw seven more pieces of the same part on what’s left of the plywood and then cut these.
Use two glued pieces of each part to form each leg of the table. Drive 1½ inch nails at five inches distance from each end and another one at the middle. This will ensure rigid joining of glued parts. Now you have to cut parts for the underside of the table. Cut two pieces 48 inches length and four inches width, and two pieces 36 inches length and four inches width from the remaining material.
Step 3 - Fix the Parts and Assemble the Underside
Spread wood glue evenly into the top surface of the leg pieces and join each pair by clamping using the C-clamp. Let this dry. Spread glue into the side potion of the four underside pieces and stand one piece at the bottom part of the table forming right angle with the edge.
Hammer 1½ inch nail on this diagonally so the tip of nail doesn’t pass through the table top. The underside must align along the edge of the table top. Do this for all the remaining three pieces to complete the underside assembly. Flip the table top. Hit 1½ inch nails at ½ inch from the edge of the table. Make five of these at each side.
Step 3 - Assemble the Legs
Flip the table top again, this time exposing the underside in top position. Take the joined leg piece and position this at the corner of the underside for support. The four inches side should face the longest side of the table. Mark the portion, then spread with wood glue at the tip where it rests on the bottom part of the table and the portions supported by the underside.
Hammer in two inches nails from outside portion of the underside driving full length into the inner part towards the leg piece. Hit another nail on the other side as well. Attach the remaining leg parts like the first one.
Step 4 - Smooth Rough Surfaces
Put on a face mask and sand down the rough surfaces. Use putty to level uneven surfaces.
Step 5 - Finishing up
You may choose to apply paint or wood varnish, whichever you prefer.