<m.Berakhot 6.6>  

If [those at the table] are sitting upright, each one says grace for himself; if they have reclined, one says grace for all. If wine is brought to them in the course of the meal, each one says a benediction for himself; if after the meal, one says it for all. The same one says [the benediction] over the perfume, although the perfume is not brought in till after the meal.

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