This granite jar on its limestone stand were set up in front of a false door in a tomb. They date to the 5th Dynasty, so about 4500 years ago.
They were used to present liquid offerings to the deceased person – I think beer is quite likely, as it was part of the standard list of desired offerings in the Offering Formula: "bread, beer, ox, fowl, alabaster, linen, everything good and pure upon which a god lives".
In some ways the same idea as the way we leave flowers at someone's grave, but rather more practical and focused on making sure the deceased had nourishment in the afterlife! I wrote about the Offering Formula for one of my subscriber articles: https://www.patreon.com/posts/offering-which-40894160