Well, I checked, and the D'Angle, as it's called, is a nifty device, but it does need some support behind the instrument. To quote:

"The D'angle must have a back behind it, otherwise it will swing inward. It needs the support. The guitar hangs securely because of physics. The weight of the instrument holds it in place."

So it wouldn't work on a table, but would work fine on a bookcase or shelf, as long as there is a wall or some other vertical element for the back of the guitar, etc., to rest against. I suppose it might work on a table if you positioned the instrument against the table leg.

I may just get one to see how it works. The picture shows something that looks great. A keen use of the laws of physics.

Bob Clayton