What is the significance in the asides between Horatio and Hamlet in Act 5, Scene 2?

There is a clear and deliberate use of asides in the first
section of Act 5 scene 2 when Hamlet and Horatio are together and then joined by Osric
who is a courtier to King Claudius.  One of the common things about courtiers is that
they serve at the whim of the king or the royal family and therefore are completely at
their mercy.  They have a very specific role to play and ultimately it is their duty to
be clever, witty and sharp, yet always do what will please their lord.  The asides
between Hamlet and Horatio reveal how the two men are making fun of this courtier for
his formal pretensions and his fawning behavior. They are having their own conversation
about him right in front of him.

When he first comes Hamlet
doesn't appear to recognize him and asks Horatio if he knows the man.  Perhaps Hamlet
does know him, but is belittling him a bit by acting as though he
never gave Osric any thought.  This is suggested by Hamlet's next aside when he tells
Horatio that it "tis a vice to know him" and goes on to make fun of his connection to
Claudius. The rest of the asides aim to make fun of how wordy and witty the courtier is
trying to be. They are making fun that he is trying so hard to sound smart that he is
actually failing in the endeavor.

The whole small scene
serves as a brief reprieve from the heaviness of the cemetery scene and subsequent
conversation and it also provides Hamlet with the fencing challenge from Laertes which
leads to the tragic conclusion of the play.