It was a textbook ladies lunch Monday at the Four Seasons, with all of the Knight Ladies gathered around their roundtable. Hosted by Casey Ribicoff, there were Nancy Kissinger, Louise Grunwald, Irith Landeau, Barbara Walters, Linda Wachner, Annette de la Renta, Duane Hampton and Mica Ertegun. The group was first cocktailed at the bar by Oscar de la Renta and then escorted to a table by the window, which they specifically requested so they could gossip in private. Nonetheless, their cackling could be heard throughout the restaurant. At one point, an overexcited Louis Marx rushed from the balcony to greet the ladies, only to plunk his hand in Annette de la Renta’s spinach.