Lunch may sometimes be included in your Applicant Day programme and, where that is the case, you would be able to see it on your itinerary.  For other catering:

Applicant Days at Canterbury
Rutherford College dining hall is open from 08.00-09.30 for early arrivals to get breakfast and there are several catering outlets on campus for you to get something to eat or drink.  The Gulbenkian café is normally open all day.

Applicant Days at Medway
No. 1 Bistro in the Rochester Building is normally open for refreshments throughout the day.  Other catering outlets on campus include Coopers, Archibald Hay Mess café in the Drill Hall Library and The Venue café in the Pilkington Building.