I used one of these when my back was so bad that using a regular computer chair wasn't really feasible. There's a weight limit of ~40lbs, so you have to mind that, but I used it to help me use my desktop from a recliner. Tower went beside the recliner, monitor and speakers went on the table-mate, and I used a wireless keyboard and mouse.

The table-mate did eventually warp from this situation, since the monitor was a touch too heavy from it, but I wasn't needing the table to be flat, just hold up the monitor, so it worked for the 2-3 years I needed it.