The Greek word that is translated here as “Master” is a not the normal word for “Master.” This one refers to someone who has authority, and not to someone who owns someone else. You could also translate it as "Boss" or "Foreman" or with a word that is commonly used to address a person in authority, such as “Sir.”
This is a rhetorical question. Jesus was rebuking them mildly because they did not trust him to take care of them. It can be translated as "You should have had faith" or "You should have trusted me." (See: [[rc://en/ta/man/translate/figs-rquestion]])