If Vivian Ventura represents those among the "demi-monde" in London who hobnob with the Arabs, the Margaret, Duchess of Argyll, could be said to represent the "haute-monde."

One of the few fashionable private addresses in London where one is likely to see Arabs is in the stately salon on Upper Grosvener Street of Margaret, the Duchess of Argyll.

"I'm actually going to have one this week," she says. "I've always had Arabs to the house. But I must say they are mainly ambassadors and people who are obsolutely charming. The others? . . . I don't think I know them if they're here."

The Duchess does admit to having some minor problems, even with those Arab friends of hers she considers "charming."

"It is awfully difficult, you know, trying to invite them. You see, they aren't very good at letting you know they're coming. You just try to do your best if they arrive." She sighs, "but they are extremely hospitable and very anxious to return your hospitality." She sighs. "It is hard though, to have them when you don't knows when they're coming."

She says all the Arab embassy types are "charming."

"Those are the ones that one really knows," she explains. "But I'd be happy to have an Arab in my house anytime. The Saudi Arabian ambassador and his wife, for instance, are absolutely divine. His wife is very chic, you know."

She aknowledges that many of the Arabs in London have had a hard time breaking into the social world, "though they haven't talked about their feeling toward the British to me. And the Jewish thing," she says."Hmmmmm, yes that is, of course, a problem for them."

She thinks one thing which may disturb some British is the fact that the Arabs gamble so much. "I simply don't understand gambling," she says. "But if they have the money I suppose they have the right to do it."

"Yes," she says, upon reflection, "I'd be happy to have Arabs here anytime. Particularly the Lebanese. I'd be happy, that is, if only I could get a hold of them. And naturally if they came to dinner with you, I'd hope they'd take off their masks."

Margaret, the Duchess of Argyll, recently did a rather adventurous thing. She took the inaugural flight of the Concorde ("I had booked it six years in advance") to Bahrain last year and then took a trip through the Gulf area. Alone. She was one of the first women ever to travel alone in Arabia.

It was, however, not only the first that the duchess has had.

Now 63, daughter of Scottish businessman, she first married Charles Sweeney, an American golfer, and was celebrated by Cole Porter in his song, "You the Top." ("You're the nimble thread of the feet of Fred Astaire, You're Mussolini, You're Mrs. Sweeney, You'r Camembert.")

But then she divorced Sweeney and married the Duke of Argyll, head of the Campbell clan of Scotland. Unfortunately, the duke in 1963 sued the duchess for divorce in what was termed the longest, most expensive and most sensational case on record in the British courts in modern times.

Today, a little short for cash, Her Grace has consented to open her 18th Century Mayfair house to paying "guests" not tourists, and to write her sizzling autobiography.

But bygones are bygones and today she is more interested in discussing her trip to the Arabian Gulf Coast.

The trip was planned for her by the Saudi ambassador and the Lebanese ambassador. "I was met everywhere, in Saudi Arabia, Bahrain, Abu Dhabi and Oman. I was looked after all the way.

"You have to be if you're a woman. I had always traveled in Arabia, the nearer parts, Jordan, Syria, Kuwait. But never that far south. I was looked after this time, of course, by the most powerful families. Wherever I went I was always the only woman on the plane, in the hotel. It is hard. And they are really just opening up. Bahrain is alright because it's run by British Airways. But Dhahran, well . . . It's very difficult and crowded."

"One is apt to miss the plane: it's hard to get the luggage. I was always the only women. Once I got to Saudi Arabia I found all the wives to be very chic with clothes from Paris, but they do put on veils in the street. They were very surprised when I went out without a veil and wearing a pantsuit. I just told them I always did it.I was very covered up, though. That's what they demand, than one be covered. I mean," she says a bit defensively. "I didn't go around Riyadh in a bikini."

The Duchess of Argyll is one of the few British who have taken the pains to try to learn the differences among the various types of Arabs.

"Most people don't understand," she says, "but Beirut was once the Paris of the Middle East. And Jordan was very sophisticated. Egypt isn't really an Arab country and certainly Iran isn't. Saudi Arabia is very pure. They actually speak the purest Arabic there. And Abu Dhabu is quite sophisticated. But I don't want to get involved with all that because I really don't understand it."

What she does understand is this:

"The British are used to absorbing people. We've had the Asians here, we've had the Indians, without raising any eyebrows. I do think people are making a mountain out of a molehill."

She ponders for a moment and then says, "Doing business with them, of course, is quite another thing . . ."