I am useing a desktop pc here. How can I fit a 2nd keyboard, mouse, and monitor while in another room? b/c that's what I want to do some times. I know buisnesses have 1 tower and maybe 50 monitors and keyboards.

In order to have 50 monitors and keyboards, the company would also have to have 50 separate desktop PCs, which would all be connected to a server. It's true, you could use another device in a remote desktop setting, but you would still have to have a separate device or desktop pc in the other room, not just the mouse, keyboard, and monitor. Perhaps I have misunderstood your question. I recommend purchasing a laptop or tablet for greater mobility.