Not entirely original. I saw an old picture of someone that made one and had to make one of my own.
Tape up the keyboard really tight before you saw a piece out of it. You’ll have to glue partial keys back in place.
Making table ‘dust’: White school glue won’t stick to clear plastic wrap. Lay down some wrap and a piece of newspaper. Lay down a bunch of glue, set your keyboard top piece on it and sprinkle with clean sawdust. After it dries, blow and shake off the loose sawdust, put it back on the wrap and apply more glue and sawdust. Repeat as necessary.
I glued some magnets to the keyboard bottom piece, but unless it’s a really thin table, it doesn’t work. However, the magnets offer a nice large surface to use package tape to tape it under the table.