If you bring food to a party, do you take whatever is left of your food home with you?
That is just flat out rude! Yes, rude! I don’t care whose party it is and how much you spent in your contribution. That bottle of wine or 8-pound ham you brought to a party was your contribution and should remain as such. Now, if the host or owner of the house insists that you take it with you that will be a different tune to dance.
So, should you have to take food to your next social gathering, don’t bring a box to take the left over with you. It probably wasn’t good to begin with if people did not touch what you brought.