I am weary of hearing the delightful words "tea party" bandied about on a daily basis and having them relate neither to tea nor to a party. In addition to causing me personal disappointment, surely this is confusing for children and foreigners learning English.
For the record, a tea party doesn't look anything at all like this:
A tea party looks like this (you may click on the photo to enlarge it) :
Of course, there is also tea. At the time of the photo, the kettle was on. You don't want to get ahead of yourself. After all, you don't want the tea to get cold before your guest arrives.