Tim Sample is the designated heir of the Marshall Dodge, Bert 'n I Downeast Maine humor. The accent is exaggerated, but not a lot. You can find people who speak pretty neah just like this.
His reference to "generic beer" comes from an earlier part of the routine. He describes how ubiquitous such products have become in the poorer Maine communities, and tells about going down to the general store, with a big jar of eggs in brine on the counter, and picking up generic products.
In particular, the generic novel: "It's got a black-and-white cover with a bah code. No illustrations. It's about this fellah. Doesn't say who..."