I am aware of what the letters in the top row of a keyboard are, but I never really thought about what words you could spell with them. I'm sure there's a lot more besides typewriter. Priority, proprietor, and repertoire are three that I know of.

As for why the letters are placed as they are, it goes back to when typewriters were first invented. The standard QWERTY keyboard layout (that we're all so familiar with) was created to prevent people from typing too fast and jamming the keys. Although, when I was younger and had a manual typewriter, I still managed to jam up the keys pretty well even with the QWERTY layout!