Just to complete the informations, here goes a site with great photos, this here showing the shop's counter with holes to keep the vases with food and wine inside. Probably this system would keep the cooked food warm inside the counter, or the wine cooled.

The text also comments on people buying warm meals in those places because they didn't have cooking facilities at their homes (insula appartments, probably). Does anyone knows if their name, "thermopolium", probably of Greek origin, has anything to do with the fact of selling warm food?

http://itsa.ucsf.edu/~snlrc/encyclopaedia_romana/wine/thermopolium.html

About the "dolium" vase, it seems that it was called like that in general and could be fabricated to dispose human fith. Here one vase of this kind appears to be useful in a thermopolium as well. Now I'm confused! *lol*

http://itsa.ucsf.edu/~snlrc/encyclopaedia_romana/wine/dolium.html