SAVE THE date! On Tuesday, October 27th, New York’s Plaza Hotel hosts a party celebrating Hilary Knight’s first “Eloise” book in eight years, “The 365 Days of Eloise.” These books — the first five — were originally written by the great Kay Thompson, whose talents could never quite be categorized. (Singer, dancer, actress, designer, author, muse.) Hilary Knight provided the charming illustrations. Now he’s doing double duty on the new one. (Little Eloise lives at the Plaza, and has many adventures in its luxurious hallways, as those who cherish the books know.) The event takes place at the Plaza’s Palm Court at 6 p.m. This is going to be one of those real “Manhattan” moments. P.S. By the way, our Hilary Knight is a gentleman, and not to be confused with Hilary Knight, the lady ice hockey goddess. She has posed for Sports Illustrated. Mr. Hilary Knight has not.