Two questions about this Orthodox practice.
1. Are the prayers before and after the meal, in Orthodoxy, prayed by all present or one person. Is it always the father? Or how is it traditionally done, if there is a specific tradition.
2. Why is "Amen" not said in the after-meal thanksgiving? I see that it is omitted for all three after-meal prayers.
1. Traditionally the senior person present says the blessing. However, the prayers in the prayerbook are only those that are used by everyone. They are said (actually sung) by all and then the final blessing is said by the priest or bishop. Therefore before the meal, you have the "Our Father" sung and then the priest blesses the food (see Q 2) and after the meal the prayer is sung by all and the priest gives the dismissal. If there is no priest, the prayer of blessing can be said by the senior person present (in a family that would normally be the father, however, if he is not present then the mother or if she is not there then the eldest child, etc).
2. There is no "amen" because there is the presumption that the prayer of blessing follows the communal prayer sung by all and the "amen" comes after that.
Example of the above points:
All (sung): Our Father, Who art in heaven ...
Priest (or senior person): Christ God, bless the food and drink of Thy servants for Thou are holy always now and ever and unto the ages of ages.
All (sung): Amen.
All: We thank thee O Christ our God, that Thou hast satisfied us with Thine earthly gifts. Deprive us not ...
Priest: God is with us through His grace and love for mankind, always now and ever and unto the ages of ages