Mayor Bloomberg woke up in a sweat the other night, he told guests at the New York Public Library’s Library Lions dinner Monday.

He was worried he had some overdue books, he said.

Judging from his calm demeanor, he was in the clear. Then he tried to put his audience at ease. “There is no truth to the rumor that we’re considering a three-tier system for library cards,” Mr. Bloomberg said, referring to the New York State driver’s license plan reached with the Department of Homeland Security.

The audience was already quite relaxed, having just polished off an early Thanksgiving dinner of acorn squash soup, turkey with stuffing and lingonberry sauce, and apple pie. The party had actually transported guests well into late December winter vacation mode, with holiday season décor of giant red lampshades and green wreaths devised by the event designer, David Monn, and a trustee, Gayfryd Steinberg. What better way to thank patrons who helped raise $2.5 million at this event alone — and many more millions throughout the years?

The red theme, which several women carried out in their gowns — among them Lauren Bush, Andrea Olshan, Elizabeth Rohatyn, Joan Hardy Clark, and Louise Grunwald — was not only in the holiday spirit. The event’s honorees — writer Jhumpa Lahiri, filmmaker Martin Scorsese, playwright Tom Stoppard, and historian John Hope Franklin — wore their Library Lion medals on red ribbons.

Past honorees, such as Rita Dove, Billy Collins, Ming Cho Lee, Shirley Hazzard, Elie Wiesel, Robert Caro, David Remnick, and Henry Louis Gates wore navy ribbons. That color was also popular for gowns — especially for one Oscar de la Renta design, with a jewel-encrusted neckline, which several women wore, including a trustee, Katharine Rayner, who added a necklace given to her by the founder of Quest magazine, Heather Cohane.

In keeping with the holiday spirit, the library passed out gifts: DVDs of Mr. Scorsese’s films and books by this year’s Lions. And it was certainly a book-reading crowd. Mayor Bloomberg told The New York Sun he is reading Walter Isaacson’s “Einstein: His Life and Universe.” The actor Philip Seymour Hoffman said he is reading Philip Roth’s latest, “Exit Ghost.” Mr. Stoppard likes to read a few at a time; right now these include “The Mill on the Floss” by George Eliot and “Wittgenstein’s Nephew: A Friendship” by Thomas Bernhard, he said.

Some guests are preparing for upcoming travel. Newsweek contributor Lally Weymouth is reading books on Pakistan. Playwright Theresa Rebeck — whose play “Mauritius” is on Broadway right now — is reading books about Rome.

Speaker Christine Quinn’s chief of staff, Peter Rider, is reading “Presidential Courage: Brave Leaders and How They Changed America” by Michael Beschloss. Mr. Rider got the book at the library’s President’s Council dinner in September.

Which just proves: Attending library parties is educational as well as fun.

agordon@nysun.com