LapGear Elevation Portable Ergonomic Lap Desk with Adjustable Cushion, Gray Woodgrain

Using this with a 15.6" laptop, I have around 5 1/2" left on the side for a mouse, when I want to use one. The ledge at the bottom still keeps my laptop from sliding down, even if it is not centered on the board. You could also use that space for a small pad of paper to take notes, and keep a pen in the phone slot. What sets this apart from other lap desks is the option of raising the back to create a more comfortable angle for working, even when not using a laptop. It is easy to carry and appears to be well-made, so overall a good purchase.