Yes, completely standard : The completion of company (and personal) paperwork in the cruise, and the need to eat and drink are why we have autopilots !
If a major catastrophe occurs, resulting in the AP dropping out* (has happened to me once), the paperwork is put down and one manually Aviates, Navigates and Communicates etc.
*the aircraft will be in a trimmed state, so there usually would be no big diversion from cruising flightpath.