Final answer:
The term 'Lap' relates to the practice of placing a napkin on one's lap when sitting at a dining table, an etiquette that should be followed immediately after sitting down. 'Tap' could refer to signaling for someone's attention but isn't a specific etiquette term. Waiting on hold during a telephone call should be based on courtesy and the call's context.
Step-by-step explanation:
The term Lap and Tap are informal expressions that refer to social etiquettes in different contexts. The term Lap is often related to the etiquette of placing a napkin on your lap when you sit at a dining table. This is typically done immediately after sitting down before starting the meal. On the other hand, 'Tap' doesn't have a standard meaning in etiquette but could informally refer to the action of tapping someone to get their attention or tapping a device. In the context of a telephone call with call waiting, the question of how long to wait on hold does not strictly relate to 'Tap' but is a matter of courtesy. Generally, a reasonable time to stay on hold would depend on the situation, but if it extends for too long, it may be polite to ask if you can call back later or leave a message.