The finger plate is "a plate that is fixed to a door near the handle or keyhole. It can be made of metal, plastic, ceramic or glass. It purpose is to prevent people's fingers from smudging the door." (Wikipedia)
But its artistic value is so much more than just its practical application.
Art Nouveau fingerplate
From Flickr...a period example.
The finger plate in context
Voysey inspired Arts & Crafts plate