I pulled one of the seldom read books from the shelf, Emily Post's Etiquette, copyright 1955. Since good manners and etiquette never goes out of style, I read with interest Miss Post's section on Grace Before Meals.
"The old-fashioned custom of giving a family blessing or thanks before meals is a very gracious one though unfortunately it is not observed as widely as it used to be. Some families are seated with bowed heads and touch nothing until the grace has been said; others remain standing--both forms are correct.
Usually the mother or the father offers the prayer, but it is sweet to allow the youngest member of the family or if there are several to let them take turns in asking grace.
There are a number of shorter and longer variations, but he following three are typical examples."
Bless us, O Lord, and these Thy gifts, which we are about to receive from Thy bounty. Through Christ our Lord. Amen.
Lift up your hand toward the Sanctuary and bless the Lord. Blessed art Thou, O Lord our God, King of the universe who bringest forth bread from the earth. Amen.
Bless, O Lord, this food to our use, and us to Thy service, and make us ever mindful of the needs of others, in Jesus' Name. Amen.
Source: Etiquette: The Blue Book of Social Usage by Emily Post, 1955. Published by Funk & Wangalls, New York