I don't really like the sound in my head when I eat, but the sound of others really grinds my gears. So glad I don't work in an office any more as it was actually enough to make me hate people who were otherwise perfectly pleasant. I am down with making a sandwich at your desk - hate soggy tomato soaked bread and worked with people who thought cleaning up after themselves in the kitchen was a sign of weakness, so I would occasionally have a picnic myself!