First of all, remember that a metaphor is a figurative comparison of two things that are not alike. Many metaphors used in Shakespeare are almost implied and it is assumed that some were so common to the language of that time that they did not even stick out.
Indeed this scene is full of metaphors, as most of Shakespeare is. I will give three that come at the beginning and are all spoken within the same conversation. You can certainly read on in the text to find several more however.
OSRIC: ...Indeed, to speak feelingly of him, he is the card or calendar of gentry, for you shall find in him the continent of what part a gentleman would see. (ln. 109-111)
Osric comes in speaking to Hamlet and Horatio of Laertes, putting Laertes up on a pedestal of greatness, honor, and dignity. He is bragging about Laertes in a way that is almost obnoxious and insulting to Hamlet, who is about to engage in a wagered sword fight against him. This metaphor compares Laertes to a business card for the upper classes, everything you would want or need in a gentleman.
HORATIO: ...His purse is empty already. All ’s golden words are spent. (ln. 130-131)
Horatio to Hamlet, saying basically, "Finally, he's done bragging on Laertes." Here, the metaphor "purse is empty" refers to the kind things Osric has been saying about Laertes, and it seems he has finally run out of things to say. Purse could be a metaphor here for Osric's mouth or his thoughts/words.
HAMLET: What call you the carriages? (ln. 154)
OSRIC: The carriages, sir, are the hangers. (ln. 157)
Osric, in describing the weapons Laertes intends to use in the swordfight, refers to the sword holders as "carriages" more than once. Hamlet does not understand what he is talking about. A few lines later he even makes the comment that saying "carriages" makes it sound like we're pulling around cannons. He then asks Osric to use the word "hangers" thereafter. "Carriage" here is a metaphor for the piece of equipment used on the body for the sword to hang.