Who is P. W. Ellis from Burmese Days and what is their importance?

Ellis is the assistant manager of another English timber company. He is a tiny man with wiry hair, pale skin, and sharp features. He is exceptionally restless, speaks in a cockney accent, and is quick to anger but also quickly calms down. Ellis' most pronounced feature is his virulent and vehement racism, which marks him as exceptional even among the other virulently racist Europeans. His hideous racism is matched by an equally disgusting sexism.