A schedule of loss in home insurance is what your provider will reimburse you on a claim for something on which you’ve purchased additional coverage—called a schedule.
A schedule is just insurance-speak for a list, usually of add-ons, clarifications, or exclusions to your policy. For home insurance, this usually refers to scheduled personal property coverage, which is coverage purchased in addition to personal property coverage that specifically protects:
Loss refers to the amount that a home insurance provider will pay you on a claim you’ve filed. Thus, schedule + loss = schedule of loss.