English Experts

[Simon Vasconcelos]

Aquele garçom não sabe servir a mesa.

[Henry Cunha]

At least two different possibilities:

That server doesn't know how to wait on tables. ("to wait" is the general work of everything from taking orders to removing dishes at the end of the meal)

That person doesn't know how to serve food. ("to serve" is the specific act of placing food plates on the table)

There may be even more appropriate terms.