Lord Snowdon was in town this week, staying at the Sheraton-Carlton Hotel. He was so taken with the hotel towels and washcloths that he wanted some to take home with him. Being a man with royal connections, he didn't just stuff a few of them into his suitcase. Instead, he asked the Carlton's resident manager, Mark Hamber, if he could have a few fluffy white towels and he left town yesterday with a free gift-wrapped set. It could be that Snowdon noticed how fortuitous it was the towels were monogrammed with a big Sheraton "S" . . .

It seems to be a week for royals. Prince Henri and Princess Maria Teresa of Luxembourg are here for this weekend's American Film Institute salute to the films and filmmakers of Europe. The films will be shown through Sept. 30 at AFI. The Luxembourg royals are staying at the Vista International Hotel, where their suite is decorated in the tiny nation's colors of the flag -- red, white and blue flowers. The chef made them chocolate boxes with the nation's flag in marzipan. Actor F. Murray Abraham, who is also staying there while attending the conference, had to settle for a chocolate Mozart record . . .

Henry Trewhitt, the Baltimore Sun's diplomatic correspondent, is moving to U.S. News & World Report, where he will be deputy managing editor for international affairs. A respected reporter, Trewhitt has also been diplomatic and White House correspondent for Newsweek magazine . . .

Singer Frank Sinatra is expected to attend the Oct. 19 black-tie National Italian American Foundation dinner in the Washington Hilton to receive the group's Life Achievement Award. The Italian military Carabinieri Band, making its first U.S. concert tour in nearly 30 years, will also be at the dinner following a performance earlier in the day at Constitution Hall . . .

It's so reassuring to know that the Miss America pageant upholds its talent and swimsuit standards. Wednesday, the first night of judging for the 1986 pageant, Miss Ohio won the talent competition by playing Liberace's version of "Chopsticks" on the piano. Suellen Cochran, 21, said she had been playing the piano since she was 7. She apparently was able to easily beat Miss Michigan Alecia Rae Masalkoski, who wore a judo outfit and whose talent was breaking soda bottles with her feet before demolishing a stack of cinder blocks. Whatever happened to baton twirling and accordion playing? . . .