It is imperative, a command. Sometimes the exclamation point is used to indicate a command. It is not an exclamation in the sense of it being an isolated word not used in any larger grammar.
I believe your question means, does HIchop mean the same thing to Klingons as Bite me does to English speakers (basically a less profane version of F— you, with an element of not caring). Almost certainly not. Bite me is an idiom that we have no reason to think translates into Klingon. A Klingon would probably wonder why you want him to clamp down on you with his teeth.