According to "Talking Dead" afterwards, the writers threw that in as one of them loves tea and showing up to work in a jacket & tie, etc. It's a neat character quirk, and I doubt it has any additional significance, though it does help set him apart as a person.
Plus, I think it's only natural if you group of survivor has a resident educated guy, to put him to wokr trying to understand the zombie menace. It does grow the universe a little without really fundamentally altering it; although now in TWD if anyone ends up on the road by themselves, they should disable their closest walker, lop off the arms and jaw, and feel a BIT safer in the wilderness thereafter.
I'm not buying that tea observation. And he was going to add something after but the host interupted him and changed the topic.
the people there are all a little stepford wife-ish. And Andrea drank the tea and got all docile after.