Without having the excavation reports or photos of the excavated object, I'd say it was a ceramic polycandelon - a multi wicked lamp. A fairly simple test should show if it has contained oil, and maybe even what sort of oil.
As for 'other uses', I'd say the most likely one would be 'drinking games' where you filled it up with some suitable drink, then passed it around the table/hall, everyone gets a drink and some sort of 'penalty' for whoever drops it or drains the last drink from it.