Below is the problem for which I have created a UML diagram with Staff as superclass and waiter, manager and hosts as subclasses, I understood other parts, except for the relation between table and cover classes, should it be Aggregation(or composition) or Association.
There are three kinds of staff members, managers, waiters, and hosts. All the staff members have a staff ID and a telephone number. Managers are also able to add and remove waiters and hosts from the system.
Tables: The tables in the restaurant each of an ID number and a number of seats. Each table is assigned to a waiter, and waiters can have any number of tables. Each table will have a number of covers (see below) that must not exceed the number of seats. The Table class should have a method to check if it is a valid seating.
Covers: Each customer that comes into the restaurant should be represented as a cover. Each cover should have a cover ID, a table number, and a food order.