If it is a hot water plate or not I don't know. Otherwise my best guess is that they are decorative serving dishes with the holes in the base added to simplify wall hanging. I enclose a picture of a 18th century hot water plate for your comparison. Notice the nice little cork in the chain, to keep the hot water inside. This information is given as an example of private conversation only and is not intended to be used as a promotion of any individual piece.
All opinions is the authors and is given as such with all hazards of judging anything from a photo.