Final answer:
The term 'zone' correctly fills in the blank, describing a practice in the dining room where servers cover additional tables beyond their assigned ones when there are fewer staff members.
Step-by-step explanation:
As dining room traffic slows down and the number of servers is reduced, zone coverage comes into play, as the remaining servers pick up tables in addition to their assigned station. The concept of zone coverage in a dining room setting refers to the practice where servers are responsible for attending to guests in a specific area, rather than just their initially assigned tables, ensuring that all customers receive timely service even with fewer staff members.