What does 2 Samuel 23:8 mean?

These are the names of David's top warriors: Josheb-basshebeth, a Tahkemonite, was the leader of the Three. He once killed eight hundred men in a single battle, all by himself. 2 Samuel 23:8 - Modern Text Bible

(This verse introduces David's most elite fighters, starting with Josheb-basshebeth, who was famous for his incredible strength and bravery in battle.)