One of the handiest saws I find is a Saber Saw. It will cut wood, metal, cardboard and even foam rubber. For cutting large pieces putting the saw on top if fine. But if you have a smaller piece, or just don't want to hold and push the saw through the material, here is a way to turn things over.
Step 1: Mount the Saw Below Your Table.
So I had made this table saw extension from a counter top sink cut out years ago. So since it was particleboard and Formica it was easy to cut a hole for the blade to stick up.
Step 2: Mounting the Saw.
The first try I drilled four holes to mount the saw's "foot" to the underside of the table. This placed the saw so low it would only work with long saw blades. So I removed the "foot" and mounted the body of the saw directly to the underside of the table with the two screws in the center. Perhaps you can do this to your saw too.
Step 3: Cutting.
So here is a photo of the saw blade finishing a cut into a drilled hole. It is really nice to hold the work piece down to the table top and watch the blade cut to the line.
Step 4: Safety and Storage.
So when I'm finished and I might use the blade again soon, I put a RED safety cover over the blade. This protects me and also the blade from being broken. When I'm done with the Saber Saw I remove the blade and cover the blade holder with the square vinyl cover to keep dust out of the blade socket.
Hope this is enough for you to mount your own Saber Saw under a table to make cutting easier and more fun!
As always, wear your safety gear and be careful.