Blessing before meal
Bless us, O Lord, and these, Thy gifts
which we are about to receive from Thy bounty.
Through Christ our Lord. Amen.
You can see this in Gregorian chant as a PDF here and here; those also have a link to an mp3 of me chanting it. There's also this handy image to the right.
Benedic, Domine, nos et haec tua dona
quae de tua largitate sumus sumpturi.
Per Christum Dominum nostrum. Amen.
Grace after meal
We give Thee thanks, almighty God,
for all Thy benefits,
who livest and reignest for ever and ever. Amen.
Agimus tibi gratias, omnipotens Deus,
pro universis beneficiis tuis,
qui vivis et regnas in saecula saeculorum. Amen.
I think I'll be producing another podcast soon with these prayers -- and maybe some other traditional ones -- spoken in and chanted in Latin.