Last time one of these threads popped up, I saw someone suggest that it might have been a holder for some of those bottles with pointed bottoms the Romans had, don’t remember the name. I’m not sure if this is a hypothesis with any level of acceptance, but it feels like it could be plausible just from looking at the thing, having different sized holes would allow different sizes of bottle to fit, and you’d want feet for each possible side that it could be resting on, which would explain the prongs.