arpon / napron / napkin
Faldage is right - rechecking my source shows that my recall was wrong, but suggests a longer story.

My source indicates that English took the Old French word naperon (= "little tablecloth") but used it for the larger covering; later the phrase for that large covering changed from "a napron" to "an apron". That source does not indicate, however, how English got "napkin" for the small covering.

Faldage, can you help further?