But if we were all happy to use lowly descriptive phrases to describe things, there wouldn't be much to do here, would there? Your "person who is an adept conversationalist at table" would be just as good as my "one who cultivates learned conversation at meals" and there'd be no deipnosophists to speak of.

You're right though; there is a mentality that it takes a word (especially a fancy-pants word) to legitimize a thing, but at the end of the day, finding some of those words is just fun and doesn't necessarily lead to logocentrism.