Fairway is a bit like Hardy's emissary in the novel. He often acts as the voice of the narrator and he helpfully delivers exposition, themes, and general commentary on topics ranging from marriage to school. As such, Fairway is sort of like the president of the Egdon chorus. He's definitely the chattiest of the bunch and he always has something pertinent to say.
But Fairway isn't just a mouthpiece for the narrator. He's a character in his own right and the little details we get about the guy show us a good family man who loves his wife, tries to help out his friends (see his attempts to pep-talk in Christian 1.3), makes smart observations, and has a decent sense of humor. He's the type of guy you'd like to hang out with, and he's definitely a fitting representative of the residents of Egdon.
And here's a fun fact: Fairway is notably the town's amateur barber, which we discover in a rather hilarious scene in Book 3, Chapter 1.