Here is some information from their web site
http://www.lyndhurst.org/home.htmlLyndhurst is located ½ mile south of the Tappan Zee Bridge on Route 9 in Tarrytown, NY. Lyndhurst is approximately 24 miles north of midtown Manhattan on the Hudson River.
CARRIAGE HOUSE CAFE
Open May-October, Wednesday - Sunday, 11:00 a.m. - 3:00 p.m.
Located in the Carriage House. The Carriage House Cafe serves a variety of salads, soups, sandwiches, desserts, wine and beverages. Reservations are not required for groups of 10 or less. Relax indoors or outdoors, or order a picnic lunch to take with you onto the grounds!
Please call (914) 524-7900 for group reservations.