The waiter Pavel, practiced medicine before becoming imprisoned at the concentration camp.
In The Boy in The Striped Pajamas, Bruno and his family have moved to "Out-With" from Berlin much against Bruno's better judgement. There are no friends, no banisters to slide down and even exploring is not allowed, with "No exceptions!" One day, whilst Bruno is looking for some way to entertain himself, he is looking for rope and a type and Lieutenant Kotler instructs Pavel to help Bruno to fetch a tyre. Bruno notices how disrespectful Kotler is towards Pavel despite Pavel being old enough to be Kotler's grandfather. Bruno cannot understand because he knows that Pavel is "a very good waiter and they, according to Father, did not grow on trees."(ch 7) Later, Bruno learns from Maria that Pavel actually used to be a doctor "In another life." (ch 13)
Pavel is Bruno's waiter who cleaned up Bruno's gashed knee after he fell off the swing in Chapter 7. Pavel explains to Bruno that he practiced medicine before coming to the concentration camp. The mother returns before he can say anything else about it.