Near the end of the birchat hamazon there is alternate wording for the beginning of a sentence for eating at your own table, or that of another person, but the end of that sentence is always in the plural (see quote below), at least in almost all bentchers. The end of the Horachamon that I refer to is worded "ours and all that is ours". But this ending sometimes does not agree in number with the beginning of the sentence which can read “me and all that is mine" or “head of household”.
So the sentence can read like this, “May the merciful one bless me, all that is mine, ours and all that is ours.” But that makes no sense to me. If the end of the sentence should agree with the beginning of the sentence, why do bentchers not include a singular wording of the end of the sentence? Is the plural wording correct for some reason that escapes me or is there another more proper wording and what might that wording be?
(Related but different question: Why no singular when referring to one parent in the birchat hamazon?)