I think the best things you can do are cable management and what economics14 said. My computer has been only on my desk and it has quite a bit of dust built up just from that. I'd also recommend investing in the same samsung monitor to set up as your second monitor.
I would try to tidy up your cables, if I were you. They'll probably gather a ton of dust/fur around them, sitting on the ground like that (that's what happens to me anyway, with 2 cats and a dog). If you don't want your mouse pad taking up more desk space, you could wrap the end around the underside of your desk and attach it there I think, though I don't know how flexible that pad is.
I would suggest a new desk since that one look kind of cramped, also just the regular tidying up and such.
More toblerone scattered across the room.
Okay thanks, I never noticed there was "AverageGaming setups" and "ShittyGaming setups"...