He felt nakedly unarmed, and wondered how far the serrated steak knife by his plate might get him. What is the meaning of this sentence
As I understand it, the expression here means: He wondered how well he could defend himself using the steak knife as a weapon. To "go far" can have an idiomatic meaning of lasting or surviving in a given situation. So the knife, while not designed to be a weapon, could still help him "get far" in a dangerous situation.