عِنْد = near, at تامِر بَيْت = Tamer house
Literally: near/at Tamer house...?
It’s explained in this description: https://www.duolingo.com/skill/ar/Omar-is/tips-and-notes
عِنْد = at the place of ...
Literally, عِنْد تامِر means "at Tamer's place". Since Arabic doesn't have a natural verb to have, we express possession differently, for instance with the use of ( عِنْد + Possessor X + ...) ≃ (Possessor X has + ...).