I'm no pro (heck, probably not even an amateur, yet), but from a technical standpoint, most floor easels are designed to stand in front of them to paint and table-top models are pretty much for sitting there to paint.
An easel, as a camera tripod, should be sturdy enough to take your brush/knife/other application devices without sliding off the table or wobbling. Lightweight is good for something you carry around, but not for something designed to hold what you work on or with. Ever notice a blacksmith doesn't use an aluminum anvil? I'd think adjusting to any size canvas/board you might use an important feature to consider, also.