Plumbing foam pipe insulation (hardware store), preferably the self-sealing variety, but if not that's OK too.
Duct Tape (I didn't need it, but it could come in handy.)
Step 1: Cut the Foam Pipe Insulation
Figure out how long you want to cut your pipe. I wanted to make protective corners and then added pieces to go between the corners to cover the length of my coffee table. Suit yourself, it is pretty simple.
Next cut a V shape out of the middle of each corner, one on either side of the pipe. Be careful to leave space between these Vs to wrap around the corner. In other words, don't wind up cutting your pipe in half by mistake.
Step 2: Apply Corners
Fit the cut pieces over your corner and then, carefully peel off the yellow backing leaving the sticky part on your table. Hold the foam carefully in place while working and then press to your surface to secure. If, for some reason, the foam does not want to stick to your surface, use a bit of handy-dandy duct tape to secure it.
I decided to add long pieces in between the corners, which is simple in comparison to the corners.
Voila! You have just baby-proofed your furniture!