Weird holes appearing on my keyboard

You say these are just appearing out of nowhere? Are you sure there hasn't been something dropped or spilled on the keyboard? To me, that looks like either a cigarette burn or a chemical spill. Are you a smoker? I know when I used to smoke cigarettes I could get careless with my ashes and cause random damage. If we can rule out cigarette burns then maybe it's from a chemical spill. Maybe something like nail polish remover or some kind of paint thinner. If you are sure it is none of those things then the next thing to consider is whether or not you share this computer with anyone else. If so, then you may have to have a talk with them.