For the second time only I think this anonymous voice from the back row agrees completely with Keith A of Hertford.

I can't remember hearing a grace in which the sentiment expressed was not reasonable in broadly humanist (or similar) terms. Were it not for a leading 'Oh Lord' or similar I would regularly be happy to join in with a hearty 'Amen'.

I think that one conservative, but very experienced, priest uses the form "We give thanks for" rather than "We thank you for" as a courtesy to in-laws and other guests.