Hello Yonisinai
the cross with four lobes is the hallmark of the city of Reggio Emilia in use in the 18th century. I do not have a more precise date.
I don't know what to say about the letters A and B. I do not think they could be the initials of the silversmith, they are struck separately and also no silversmith registered in the Duchy of Modena and Reggio has those initials.
Regards
Amena
I don't have photos of many profane objects, most are sacred objects.
This bowl looks like yours, and it also has two letters stamped on it. Again, no registered goldsmith has these two initials. There are probably many unknown silversmiths.
Regrds
Amena