I went to friends one year for Thanksgiving when I was single. My friends wife asked prior to grace, “What are you thankful for?” and we went around the room and expressed what each person was thankful for. I thought it was a great idea, especially for younger kids as it helps them to articulate their thoughts and builds their confidence speaking in front of large groups!
This was a tradition in my family as well.
With 50 guests, however, it could be difficult to hear each person, and it could take 5 minutes or more. As an example, we do this sort of prayer every week in my first grade religious education class. In the beginning, it took 5 minutes just to get through these 13 children saying thank you to God for just one thing.
Would it be possible to get a piece of poster board and some pens set up near the door? As each person/group came in, someone could direct them to write down something they’re thankful for. In your prayer, you could give thanks to God for everything written on the board.
If you have any musical ability, you could make copies of the song
“For the Beauty of the Earth” (click on song title for link) and have everyone sing a verse or two (or three or four or five) as your grace.
You could also recite some of the song’s lyrics as your grace:
**1 For the beauty of the earth,
for the glory of the skies,
for the love which from our birth
over and around us lies.
Refrain:
Christ, our Lord, to you we raise
this, our hymn of grateful praise.
2 For the wonder of each hour
of the day and of the night,
hill and vale and tree and flower,
sun and moon and stars of light, [Refrain ]
3 For the joy of human love,
brother, sister, parent, child,
friends on earth, and friends above,
for all gentle thoughts and mild, [Refrain]
4 For yourself, best gift divine,
to the world so freely given,
agent of God’s grand design:
peace on earth and joy in heaven. [Refrain]**