The Ghost of Hamlet's father relates how he was killed by having poison poured into his ear. We see a very quick flashback of King Hamlet's ear swelling up while blood and pus pours out. This is graphic, but lasts less than one second.
While the First Player is recounting the grief of Hecuba, we see brief flashbacks of the destruction of Troy. There is a lot of chaos, but nothing graphic or bloody.
Hamlet kills Polonius by stabbing him through the curtain multiple times. He falls to the ground and blood comes pouring down over his face. Very brief and not very graphic.
Hamlet angrily throws Ophelia across the room when he thinks he is being spied on.