The Strathmore tea only happens once in awhile, and typically on a weekday for whatever reason.
I think Normandie Farm in Potomac does tea:
http://www.popovers.com/ Not sure how elegant it is.
And my friends took me to a really lovely afternoon tea at the Mandarin Oriental just this past spring and it was NOT buffet style, as PP said. Maybe things have changed, but when we went in April, each person was served a little tiered display of savory and sweet items along with a large selection of tea.