What does hamlets comments mean A man may fish with a worm that hath eat of king and the fed worm?

In Hamlet's comments, he compares a worm used for bait to a king. He implies that even though the worm may have eaten the flesh of a powerful monarch, it is still being used as a lowly lure for catching fish. This metaphor highlights the contrasting roles that people play in life and how status and power can quickly change.