The Food Standards Agency's 2-hour rule for buffets

UK food safety guidance recommends that food left out at room temperature, such as a buffet spread, should not sit for more than 2 hours before being refrigerated or discarded, since bacteria multiply fastest between 8°C and 60°C, sometimes called the "danger zone". For a long event, plan to bring food out in batches rather than laying the entire buffet out at once, which also keeps it looking fresher for longer.

Finger food quantities for a British wake or wedding

UK caterers traditionally plan finger food buffets (common at wakes, christenings, and casual weddings) at around 10-12 pieces per guest for a 2-3 hour event without a sit-down meal, roughly double the canapé count used for a shorter pre-dinner drinks reception.