If you can handle the small talk, if your suit isn't too rumpled and you're wearing a tie, you can probably dine in Washington free, uninvited and in style at almost any time of any day.

Embassies, parties on Capitol Hill, and receptions in the big hotels offer tables laden with goodies and spirits to the person with a little chutzpah.

"The hotels are still the best," was the opinion of one Capitol Hill intern who spent one whole year eating free.

"You can pick and choose from the schedule in the lobby. If you didn't like one hotel you could go to another until you found one you liked," he said.

"If someone stopped you at the door you just told them which congressman you worked for and you were welcomed."

I recently spent a week freeloading. During that time I went to several embassy receptions, two parties on the Hill and two hotel cocktail parties.

There was no challenge at any of the doors I walked through. For the most part I was greeted warmly.

To get into any of these affairs it helps to wear suit and tie. You've got to look like you belong. And act like, of course, you were invited.

No one quite knows who the freeloaders are or where they come from, although they usually know everyone else. They are usually charming, personable, with a tiny bit of knowledge about a lot of things. They love parties, chatting freely with the titled, and, of course, the free booze and food that go along with the parties.

The freeloader is expert in getting by the desk and once inside he'll chew on a few cold shrimp, a couple of hors d'oeuvres, swill down three martinis, pick up a couple of business cards and head for an 8 o'clock embassy reception for a hot meal and more booze.

A social secretary for a large embassy said. "We know who they are, the gate crashers, but after crashing enough gates they somehow get onto guest lists.

"One sweet old lady worked this scene for years. She collected ambassadors like they were movie stars. People liked her and she never bothered anyone."

To a freeloader, crashing a party at the Embassy of the Soviet Union could be likened to a baseball fan holding seven free World Series tickets.

One man, after many years managed to get on the great list. (He never got in as a plain freeloader). He was a caviar freak and always brought a date along who couldn't stand caviar. His gimmick was to line up a few times at the groaning board, fill his plate with the exotic fish eggs and urge his date to do the same so that he could gobble all of it.

The social secretaries who have the job of keeping a full guest list are swamped with requests from people trying to get on their list. In some instances congressmen have interceded to get constituants into a party.

As one secretary said, "It isn't bad for an ambassador to see a full house."

The Diplomatic Blue Book lists about 130 embassies and the dates of their national holidays. Except for the Iron Curtain countries, most embassies are fairly lax on security.

Invitations are sent out beforehand, but they are rarely required for entrance.

For the most part the parties reflect the wealth of the country as to how elaborate the flow of liquor or food may be.

Is is not unsual for embassies to share the same date on a national holiday.

This happened recently to the embassies of Bahrain, a rich oil country on the Persian Gulf, and Bangladesh, a new, struggling nation next to India.

Bahrain held the first party, a lavish affair in the Crystal Room of the Carlton Hotel and the second, Bangladesh, at its Chancery in a Bethesda suburb. That one was more like a nice neighborhood house party.

When you are freeloading the other freeloaders can spot you and take you into their trust by whispering, "Mark this down, the embassy of such and such has great parties. This one is Saturday night at the Statler."

During my freeloading days I did pick up a few friends. Most of them had seen earlier picking off shrimp from the giant ice sculpture at the Bahrain party, but none seemed to make it out to Bethesda to shake hands with the ambassador from Bangladesh.

Somehow I began to think I had run across a bunch of snobs.

The professional freeloader does not stop at the embassy. They will have an ear to the biggie on Capitol Hill where a reception of some kind might be going on every night.

A public relations man familiar with the Hill scene said there are many parties and receptions each year. A lobbyist might have a client he wants to impress; he will throw a party for him and he needs to pack the room. He might point to some guest and say, "He's very important man in Sen. 'Blah's' office."

"Access to these affairs is really easy, and quite a few younger people on the Hill with low salaries take advantage of these freebies.

Recently a 39-year-old Senate aide was taking a friend of his to a concert at the Capital Centre. He had access to a Sky Suite, one of those "it'll-be-empty-if-we-don't-use the tickets," they said. He wasn't sure if there would be food. "Sometimes they come by and open the private stock, and sometimes they don't."

Worrying about the possibility of no food he said to his friend, "You know what this means. We have to make a detour over to K Street to get something to eat. Some lawyers, some Christmas party or something . . . "

Of course freeloading can backfire, as it did to me once while on an assignment at a hotel.

It was a long wait for the interview subject to appear and the area was rather dry. A convention of some kind was in progress in a room down the hall There was a bar and an open door. On a table by the door there were stacks of name cards, the kind you paste on your suitcoat.

Without bothering to put my glasses on I stuck one on my lapel, walked to the bar and ordered a cold beer.

While I was sipping a woman came over, looked at my tag and in an excited voice said, "Oh, Congressman, I'm so glad you could make it."

My retreat was hasty. And I slipped the name tag back onto the pile, still clutching my cold beer, making good my escape.