Well... not actually, Norman ... Splenda is a sugar substitute... low calorie and one of about three popular substitutes. They are all in different colored little paper sacks on dining room tables. Splenda is yellow, Sweet'n Low is Pink and Equal is blue.
Tea, by the way, so important to U.K. citizens is available here in the U.S., but rarely demanded by our populace, so don't expect much in the way of either your quality or selections. We do do coffee though! Starbucks on every other corner, plus some really good smaller chains... my personal favorite is Caribou. By the way your mince is our hamburger, our biscuit is not repeat, not a sweet to be enjoyed at tea (that's a cookie here). A biscuit is primarily a breakfast sort of roll that looks somewhat like a scone, but tastes nothing like one. Try it with sausage gravy, especially in the South if you're there...
Welcome to the U.S., by the way!