The discovery was made during ongoing excavations at the Carmel Mountains near Haifa in the north of Israel, an area inhabited by a prehistoric tribe 13,000 years ago.
"We know that prehistoric men buried their dead and mourned them, but we didn't know they also held ritualistic meals near their graves," Guy Bar-Oz from Haifa University told China's Xinhua news agency.
"We know they are leftovers of a big meal because the remains are not complete bones; many of them were broken and bone marrow had been extracted from some of them, which lead us to believe they were not remains of complete animals," Bar-Oz said.
Marks on the bones suggested the ancient inhabitants "used flint tools to cut the bones and the meat when they were doing funerary offers," he said.
Archaeologists at the Carmel site have unearthed 29 skeletons of the Natufian people that lived in the Levant region between 12,000 and 15,000 years ago.
"Our thesis regarding this find that we unearthed in only one grave so far is that all the tribe would sit together near the tomb because it can accommodate a lot of people and has a great view of the mountains," Bar-Oz said.
The Haifa Natufians roamed Israel at the end of the Ice Age and ended the nomadic life to eventually settle down, the researchers said.