You may be right that all Highbury was a snobbish community, in the sense that many of it's inhabitants discriminated between people on the basis of minute gradations of social rank. In this I'd see Highbury as a mirror of wider English society of the time, when social rank *did* matter. As I have posted elsewhere, the egalitarian ideals which we value highly today were then decidedly out of favour as a result of the French Revolution, the Terror and the Napoleonic wars.

I think you have omitted from your hit-list of Highbury snobs the biggest snob of them all – Augusta Elton. Chambers Dictionary defines a “snob” as:

“A person who sets too much value on social standing, wishing to be associated with the upper class and their mores, and treating those viewed as inferior with condescension and contempt.”

I'd say that the insufferable Augusta fits this definition perfectly. ;-D

Regarding the Coles' dinner party, their guest list comprises Mr Knightley, the Westons, Frank Churchill, Emma, one other 'proper unobjectionable country family', andthe male part of Mr Cox the Highbury lawyer's family. The less worthy females were to come in the evening, with Miss Bates, Miss Fairfax, and Miss Smith.

The Cox family were in trade, becoming prosperous through some sort of business in London. Their dinner party guest list suggests to me that their party was not intended as a jolly get-together of their closest friends, but principally as an opportunity for networking and cementing potentially advantageous acquaintanceships. I'd guess that the all male conversation over the port after dinner was an important opportunity for this.