How can we do this in Arena software as model ?

A restaurant with n-tables (in our case n=6), Customers arrive at the entrance at the restaurant (station where the customers arrive). In case the restaurant is full (no available table), simply we set the rule that the arriving customer would leave. If the restaurant has available tables, the first available table is assigned. Suppose the arrival rate is according to expo(5). Suppose the duration in the table (20 minutes) and table 2 (10 minutes).