I'm not at home or I would just take a photo, but I have a like 17 or 19" tablet fitting on my little 4 foot by 4 foot or so desk + laptop, and it works alright xD I drew a little diagram of how it fits:

now that I'm looking at it tho my table might actually be 3x3 lol...
looking at your space I think it might work if you move the circle thing up out of the way, move the keyboard up closer to the monitor (kinda like a laptop, if you just rest it right under. You only need your left hand to reach for keyboard shortcuts mostly) and adjust to having the mouse front and center like in my drawing. I basically just use that front center area for all my misc. stuff (mouse, tablet pen, live life on the edge and have a cup of water, etc.) Not ideal and I wish I had more space, but it works well enough xD