Horatio: Friend and confidant of Hamlet.  Hamlet shares with Horatio all of his experiences and misgivings in the situation involving his father.  Horatio is left alive at the end to tell of the events leading to the deaths of Hamlet, Laertes, Claudius, and Gertrude.

Rosencrantz and Guildenstern: Childhood friends of Hamlet.  They are recruited by Claudius to first discover the cause of Hamlet’s madness.  Eventually, their orders are changed to escort Hamlet to England where he is to be killed.  They are killed instead when Hamlet discovers the death order and changes it to apply to them.

Fortinbras: Prince of Norway.  His father was conquered by King Hamlet and initially seeks revenge.  Ambassadors sent by Claudius are able pacify him.  Upon his death, Prince Hamlet names Fortinbras heir to the throne of Denmark. 

Francisco, Marcellus, and Barnardo: Danish soldiers entrusted with the watch who first spot the ghost.

Osric: A courtier.

Reynaldo: Servant to Polonius.

Voltemand and Cornelius: Courtiers and Ambassadors who prevent an invasion by Fortinbras.

A Gentleman, A Lord, Ambassadors from England, A Troupe of Players, Two Messengers, Sailors, Fortinbras’ Captain, Two Gravediggers, A Priest, Attendants, Lords, Guards, Musicians, Soldiers, and Followers of Laertes

Metaphor Analysis

ACT II, SCENE 5, LINES 105-111
"Yea, from the table of my memory
I'll wipe away all trivial, fond records,
All saws of books, all forms, all pressures past,
That youth and observation copied there,
And thy commandment all alone shall live
Within the book and volume of my brain,
Unmixed with baser matter."

Hamlet wants to wipe his memory clean, as one would erase a slate.  All of the images he has of his mother and uncle are insignificant to him now in the face of their betrayal.  He will erase those images in his memory so as to not be deceived again.  With his memories erased, Hamlet will be able to properly avenge his father's murder. 

There are many images of sickness, disease, wickedness, blemishes on the body, and other loathsome things that are metaphorically descriptive or the unwholesome condition of Denmark.  Examples of this are on most pages.  A few examples are found in the following places:
3.4.43
4.5.18
3.4.74
1.4.27