Tea And Company Do It British-style In Philadelphia, And Enjoy The High Comforts And Heavy Carbohydrates That Are Part Of The Tradition. Just Be Careful Who You Bring Along.

Teatime in America is no longer the exclusive domain of genteel dowagers, tweedy Anglophiles or avid coffee-shunners. Nowadays you might spot high- powered professionals forging out a deal over a plate of finger sandwiches, or garden-variety tea-takers who realize that this repast is the perfect antidote to the natural dip in energy that most people experience in the late afternoon.

It's a sort of wide-awake siesta for on-the-go Americans.

In essence, tea is hot. (And tea should be hot, although a troubling fact of the Philadelphia tea scene is that the water served is usually cooler than acceptable.) And even though this is not the traditional tea season, teatime is as much an antidote for a cool or rainy summer day (sound familiar?) as it is for the middle of a bone-chilling winter afternoon.

In Philadelphia and its environs, tea has had its ups and downs; establishments that offered a formal three-course tea a few years ago have checked out of the business, and other restaurants have stepped in.

Here's a rundown of some of the places where you can take tea today and there investigate such teatime-oriented questions as: What, if anything, is accomplished by crooking your little finger when you raise the cup to your lips? Do you break off hunks of a scone, or slice it across like an English muffin? How much double cream can you stuff your face with before your conscience kicks in?

And: Why haven't more people discovered this terrific way to pass a few hours in the afternoon?

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The newest tea experience in town is at the Ethel Barrymore Room in the Hotel Atop the Bellevue. At $12 per person for the full three-course tea ''meal" - before tax and tip - it's also the most expensive.

Granted, it's also the prettiest. The Ethel Barrymore Room, done in turquoise and pink, is highly attractive. There's a painted dome, and an enormous flower arrangement stands in the center of the room. There are couches, and chairs with gilded-shell backs and huge pedestal lamps that drip crystals. Perhaps the management will savvy up and tidy up the top of the balcony, which is visible from some of the seats.

The tables are tiny, too small to hold more than one course at a time. But that doesn't matter when you consider that the rinds of the lemon slices are etched decoratively, the fork is a European three-pronged style with one sharp tine for cutting, and the service is Wedgwood's delicate wild-strawberry pattern?