Tiny roman altar needs RAT comment

[zakhx150]

I have here an image of a small (c.80mm high) soapstone altar from Roman Britain found in a museum archive in a box full of antlers. The patera on top is drilled in the middle to a depth of c.15mm and could therefore be used for votive supplications of wine. The rear face is missing and the remaining three are apparently un-inscribed. I have in my head an image of such a thing being used on small family altars, with associated figures of Gods and Goddesses but might find practical use elsewhere??

Has anyone seen anything like this of stone? I have seen bronze examples before but never of very well worked and highly polished stone in this manner.
[Vague references to associated material would be lovely, though I fully invite conjecture, comment, criticism and compliment]