The Redskins' Joe Theismann and his lady Cathy Lee Crosby were out on the town this weekend for the running of the Washington, D.C., International horse race. Joe, in black tie and white silk scarf, and Cathy, in a low-cut black dress, showed up at the Italian ambassador's residence Friday for the party for some of the international guests and Washingtonians planning to attend the race at Laurel the following day.

Theismann said he had no intention of getting into buying racehorses for his Middleburg, Va., farm, where he and Crosby keep riding horses for themselves and Theismann's children. He said Crosby had encouraged his interest in horses, and added, "Besides, if you work for Redskins owner Jack Kent Cooke, you have to be interested in horses." Former Democratic National Committee chairman Robert Strauss and his wife Helen, who were also at the embassy party, said they have owned racehorses and that they go to the track as often as three times a week.

Among the other guests at the party were Supreme Court Justice Sandra Day O'Connor and her husband John; television celebrities Eva Gabor and Merv Griffin; Commerce Secretary Malcolm Baldrige; television producer Nancy Dickerson and Texas oil man Bill Moss; Washingtonian magazine owners Philip and Eleanor Merrill; and NBC newsman Roger Mudd and his wife E.J.

Theismann and Crosby, obviously deciding it was too far to drive home to their Middleburg farm that evening, checked into the presidential suite of the Bristol Hotel, complete with complimentary champagne and a black marble whirlpool tub. That's one way to get ready for tonight's battle with the Giants. End Notes

Sen. Arlen Specter and his wife Joan, who is a Philadelphia city councilwoman, were sitting in a theater on fashionable Rittenhouse Square Friday, watching the movie "Agnes of God," when someone grabbed Joan Specter's $4,000 sable-lined raincoat and escaped. The senator rushed from the theater to flag down the police but the thief got away . . .

Nearly 1,000 people paid $50 each at Saturday night's Food for Christmas Ball at the Shoreham. With comic Mark Russell and the hot singer Whitney Houston entertaining at the ball, the sponsors, Temporaries Inc. and WKYS radio, said enough money was raised to buy 140,000 cans of food . . .

Speculation abounds in Middleburg this weekend with a sighting of investor, financier and corporate takeover expert Carl Icahn dining at the Coach Stop Saturday evening. Icahn is the one who paid $7 million for the Newstead Farms broodmare Miss Oceana. Now the word is he is looking at Upperville's premier, 514-acre Newstead Farms itself . . .

Novelist D.H. Lawrence, once considered a writer of "dirty books" by some elements of literary society, has finally -- 55 years after his death -- achieved his place in Poets' Corner at Westminster Abbey. His book "Lady Chatterley's Lover" was prosecuted under Britain's Obscene Publications Act in 1960 but was not banned. Lawrence's memorial stone, carved with a phoenix and the inscription "Homo sum! the adventurer," from his essay "Climbing Down Pisgah," was unveiled Saturday alongside "Alice in Wonderland" creator Lewis Carroll, romantic poet Lord Byron and tempestuous Welsh writer Dylan Thomas . . .

When House Speaker Tip O'Neill decided to retire, his appointments secretary, Christine Sullivan, made her decision to run for the Massachusetts state senate. But in planning a campaign kickoff party tonight, she neglected to notice that O'Neill wouldn't be able to attend because of a previous commitment. She talked to Bob Bedard, who runs Art PAC, a political action group for the arts, and came up with a substitute: At her kickoff will be a "soft sculpture" of the speaker by Lisa Lichtenfels. Apparently a "soft," half-size O'Neill is better than no O'Neill. Sullivan will not be without a political celebrity, however. Rep. Mo Udall has offered to give the kickoff speech. O'Neill will get to meet his likeness, however, the following night when Art PAC sponsors a political art show in the Hyatt Regency Hotel on Capitol Hill. There, Tip's doll will meet a Ronald Reagan doll, which is said to be so correct that it even has a bullet wound scar . . .