... to think that putting a stemmed glass on a coaster is idiotic

[Jizelle]

I took in a package for the neighbour today and when I took it over she offered me a glass of wine... yes please. She then rushed at me with a coaster when she noticed I was about to put it down on the side table.

Coasters are to prevent condensation from marring the table. The foot of a stemmed glass will not have condensation. All a coaster does when a stemmed glass is involved is to make an unstable target for putting down something that is already top-heavy. It really is alarmingly stupid.

She clearly thought you looked like a dribbler.

This!

Or perhaps she's seen the state of your house and is simply judging you on that.

Alarmingly bad mannered and very non-u to draw attention to these things OP. Next time you take in a parcel for her and she pops round you can show her how Margo Leadbetter/you serve a glass of wine ;)

YABVU. Try it for a few weeks then pay to have your table re-polished.

She clearly thought you looked like a dribbler

Hmm, just noticed OP's name, could be a clue.

Couldn't you just be grateful for the drink! Maybe she wouldn't have bothered if you were going to analyse how she offered it after all it was a kind gesture.
I would be saying cheers for the parcel and bye to you next time!