Jewel McCabe found her dinner partner, President-elect Ronald Reagan, "perfectly charming and very sincere" as she chatted about the problems of New York and of blacks.

"I didn't think it appropriate," she said in a phone talk with a reporter, "to bring out a list of recommendations," but the conversation through dinner did touch on education, black involvement in the economy and so forth.

McCabe is president of 100 Black Women, an organization of 600 blacks, most of whom are prominent in business, education or the arts in New York, though a third of the membership consists of young women just beginning to make their way, McCabe said.

The dinner was given by Brooke Astor, the leading force in the foundation that memorializes her late husband, Vincent Astor.A lifelong Republican and a leading American grande dame, she wanted to "do something" for the president-elect, and rallied from a quite severe cold (she was in bed yesterday) to fling one of the most envied dinners of the season. It was held at her elegant Park Avenue apartment.

"People phoned after the dinner [which was Tuesday night] to say how warm they thought it was," she said, "and I think it really was.No matter who you are, or how you voted, I think Americans want a president to succeed and want to give him some support."

Mr. and Mrs. Reagan met some people -- like McCabe -- they might not have known. Neither of the state's senators, nor the city's mayor, was invited, because it was not a political affair, but a gathering -- as the hostess hoped -- of people all concerned with the future of New York apart from political office.

Henry Kissinger and Douglas Dillon, however, may have served to represent the field of politics, and you might even count Happy Rockefeller, widow of Vice President Nelson Rockefeller.

Among business and financial figures were Walter Wriston, chairman of Citibank, Lewis Preston of the Morgan Guaranty Trust Co. and David Rockefeller of Chase Manhattan Bank. The garment industry wing was rather fashionably taken care of by Oscar de la Renta and Bill Blass, clothes designers.

Franklin Thomas, president of the Ford Foundation and Vernon Jordan, president of the Urban League, were present, and New York mass-media figures included chairman, editors and reporters in various combinations from The New York Times, The Wall Street Journal, the Daily News and the television networks.

McCabe's father, Hal Jackson, was a pioneer black broadcaster of the 1930s, Jewel McCabe observed, "and some of it must have rubbed off on me." She is director of community and governmental affairs for WNET, Channel 13 in New York and has a public relations background from earlier work with the New York governor and the Urban Coalition. The 100 Black Women organization was founded in response to the city's 1975 financial crisis, when it seemed important for representative black women to throw their support to the city and to become identified with its affairs.

"Thanks to Brooke Astor's logistics," she said, "everybody was able to meet the Reagans, and the president-elect's willingness to mingle with such a cross section seems to me a very good step."

Astor, before getting back to bed and praying she isn't catching the virulent flu that's going around, said McCabe is bright, beautiful, got on wonderfully with the Reagans and "had the best seat in the house."