It's easy to understand. Tea parties aren't like most other gatherings. At a tea party, if you get the beverage right, then you've pretty much got the whole party right. But to really make it an event to remember, you have to add some delicious edibles.
Fortunately, that's not hard to do. Follow this simple rule: something savory, something sweet and something with which to cleanse the palate.
For the sweet stuff, consider the tea you're serving. Is it a traditional black tea or an orange pekoe? Then perhaps you want to serve a muffin or a scone. You can make straightforward blueberry muffins or you could try something a tad more exotic like a cherry chocolate chip scone made with heavy cream. Avoid serving anything with a fluid interior – no jelly donuts! At no point should your guests fear they're going to make a mess or worse spot their dress or tie.
You can also consider the tea biscuit – which is a kind of sweet cracker. These are easy to pick up at most quality grocery stores, but you can also make them. Essentially, they are butter, sugar and flour cooked at a high temperature. They melt in one's mouth and go nicely with a tart tea like Oolong tea.
For the savory dish, you want o be sure that you are thinking along the lines of finger foods. Finger sandwiches are ideal. They are satisfying, neatly compliment the sweets, and don't make much of a mess. Make these in advance and serve them on your best serving china.
How about the traditional cream cheese and thinly sliced cucumber on a hearty white bread? Or sliced avocado with smoked turkey and and tart apples on wheat? Try a little crispy bacon with melted swiss on Rye. You can cut the crusts off and even make delightful little shapes.
Cold water should be on hand, as well as some pickled ginger or fruit lightly dusted with sugar or apple juice concentrate. Be sure to put out napkins!