My book page number are different than yours, but here's a quote from Slim as he's introduced.
A tall man stood in the doorway....Like the others he wore blue jeans and a short denim jacket. When he had finished combing his hair, he moved into the room, and he moved with a majesty only achieved by royalty and master craftsmen. He was a jerkline skinner, the prince of the ranch, capable of driving ten, sixteen, even twenty mules with a single line to the leaders....There was a gravity in his manner and a quiet so profound that all talk stopped when he spoke. His authority was so great that his word was taken on any subject, be it politics or love. This was Slim, the jerkline skinner. His hatchet face was ageless. His hear heard more than was said to him, and his slow speech had overtones not of thought, but of understanding beyond thought. His hands, large and lean, were as delicate in their action as those of a temple dancer.
Slim is described a "royalty," a "prince," a "temple dancer," ageless, an "authority," a "master craftsmen," his word is law.
Slim is Steinbeck's working-class hero, a man who could be boss (who is better than the boss and Curley), but who refuses to put himself in a position of authority. He knows power corrupts, and he refuses to victimize his fellow co-workers.
Slim is top of the food chain: the majestic horse, the lion king. He defends George and Lennie from Curley, but he cannot prevent the ultimate tragedy that befalls Lennie at the end.