Strange cup please help

Hello, this is my first posting. I have recently bought this small cup/bowl at a vide greniere in France and have no idea of the origin. It looks as if it should have a specific use due to the design.

It has a different pattern on the back/front. It has a circular finger handle with a thumb plate over the top of the handle.

Underneath the thumb plate there are some markings which I believe to be a 5 pointed star within a square. There are 5 letters between the points of the star. They look like, starting from top left going clockwise, P E B V M/N. Next to this another square with the numbers 12G in it.

It measures 10 cm internal diameter and 3.5cm tall.

I would be gratefull for any information.

Thanks :question:
Cup front.JPG

This is a sommeliers cup.
used for tasting wine.
Most likely it is silverplated.

Thank you for that. This site is really informative and good to read through the posts.

Cathy