It was billed as a dinner for former German chancellor Willy Brandt and the Brandt Commission. Which it was.

It was also an excellent opportunity for a vice president of the World Bank to do some serious chatting with the president of the Inter-American Development Bank and for the president's ambassador to the Middle East to make a nice deal with the director of the International Development Cooperation Agency and for the economic minister of the Netherlands embassy to. . . .

You get the idea. At dinner tables full of international monetary and political folk whose Concordes often pass in the night, things get done.

"Tell you what," Mideast ambassador Sol Linowitz was saying to Thomas Ehrlich, director of the International Development Cooperation Agency, "the next time I go over there, come aboard on the plane."

"You get a deal," responded Ehrlich, flushed with pleasure.

"There's two things you owe me now," answered Linowitz, declining to explain what the first one was.

That was at Table No. 1 in a ballroom of the Four Seasons Hotel last night. There were a bunch of others, holding some 60 people, where who-knows-what was going on.

Up at the dais, meanwhile, was Brandt. Man of the evening, often called a visionary among European leaders. And chief architect of the commission's report calling for rich nations to help poor nations.

"It's not so any more that we can help the poor so that they can help themselves," he said. "We must help the poor so that we can help ourselves."

The commission, a group of 18 internationally prominent men and women, recommended in a report released Tuesday a goal of $60 million in development funds by 1985, compared to $20 billion today. It also denounced the amount of money spent on arms.

Not a harmonious suggestion, perhaps, in a week when the president of the United States is sending Marines to the Arabian Sea. Brandt admitted this.

"I do not expect radical changes within the next few years," he said, leaning his head on his hands, "but within a decade, important changes must take place."

A little later, he personalized this in a softly spoken speech to guests. "I'm old enough to have experienced twice in my life how hunger grew out of war," said Brandt, a man who fled Nazi Germany in a fishing boat stocked with a few shirts and one copy of 'Das Kapital.' "Now I'm afraid that children and grandchildren could get in a situation where wars grow out of hunger."

Not all of the evening was so sobering. At a pre-dinner cocktail reception, there was actually one tiny knot of international sorts dicussing the great world of books. With glee.

"We were talking about French literature -- Stendhal," explained Hans Michael Ruyter, economic minister of the German Embassy.

A little later, the name of a familiar 16th-century playwright popped up.

"Let me tell you," William Clark, vice president for external relations of the World Bank was telling a receptive guest, "Mr. Oritz-Mena has the best collection of Shakespeareana in the world."

Mr. Oritz-Mena is Antonio Ortiz-Mena, president of the Inter-American Development Bank, who at that point suddenly found himself owing a favor to Clark. "Now I've done your public relations for you," was how Clark put it, quietly, after the guest moved on to another circle of chit-chat.

Among the notables who had drinks, then a dinner of chicken and some kind of pineapple fluff, were William D. Rogers, former under Secretary of State for economic affairs; Davis Aaron, deputy assistant on the National Security Council; Mary King, deputy director of ACTION, and her husband, former Carter drug-abuse adviser Peter Bourne; Daniel Schorr of National Public Radio; and Paul Bomani, the ambassador of Tanzania.

Also attending were Katharine Graham, chairman of the board of the Washington Post Co.; Peter Peterson, former commerce secretary; and Shridath Ramphal of Guyana, secretary general of the British Commonwealth. All three served on the commission.