Last week I took a client out to lunch and he said grace before eating his meal. This was not a big deal because he did not ask me to participate in the prayer with him. I did not think that waiting to eat for a few seconds while he quietly prayed was a significant imposition on my meal time and he appreciated that I was respectful of his tradition (we had previously discussed that our traditions are different).
And sometimes The Wife and I are guests in someone else's home, and they say grace before their meals. In that case, we respect their traditions -- we are the guests and they get to call the shots for how things happen in their own home, end of story. If the hosts ask us to join them in the prayer, then we go through the motions and offer no signs of insincerity or distaste.
In the converse situation -- religious people coming to a secular house for a social event and wishing to pray before a meal there -- my general opinion is that "[w]aiting a few seconds while the [religious guests] pray is a reasonable accommodation for hosts to make to their guests. Not using their prayer to evangelize is a reasonable accommodation for guests to make to their hosts."
But that line gets a little fuzzy if one of two things happens, which really are the same thing. First, if the prayer is long, loud, or if its content is intended to evangelize. The social awkwardness of such a situation is obvious and I would hope that no religious person with good manners would behave in such a way while a guest in someone else's house.
The second issue, I think, is more subtle -- at least for those religious out there who habitually invoke their deity before eating. It has to do with the way in which the prayer takes place.
Plenty of times, a religious family will begin a prayer before a meal by having everyone at the table hold hands and form a circle while someone prays out loud. Other times, there will be a chanting of a common prayer. Sometimes both will happen. The manner of prayer demands that the atheists participate. I fully recognize that this style of invocation is intended to create an atmosphere of family and love and community by the people initiating the prayer. The request to join in the prayer was likely well-intentioned, but the same time, it really puts a non-believer on the spot.
Here's why I say the evangelizing and the hand-holding are really the same thing: by inviting the atheists to participate in the prayer, the prayer becomes an evangelical device. The atheist must either refuse to participate, which is socially awkward, or participate in an insincere act of worship. Or, given that this is taking place in the atheist's house, the atheist can refuse to allow the prayer to proceed, which is even more socially awkward because it starts a confrontation between host and guest.
If our guests want to fold their hands or clasp them together and offer a few words of praise and thanks before eating a meal in our house, I for one have no problem with that. But I do find it something of an imposition if I am asked to participate in the ritual myself, in my own home.
It's like wearing shoes indoors. Some families have a deal in which you leave your shoes at the doorstep when you come in the house. This may be a cultural tradition, it may be to avoid tracking mud and dirt on the carpet, whatever. It's not for a guest to question that tradition; the guest should, without argument, remove their shoes upon entry and leave them at the doorstep until it's time to leave. But in our house, we often walk around with shoes on and you're welcome to do that, too. You can take your shoes off if you wish and we don't mind that.
But you wouldn't walk into my house and ask me to take my shoes off. Same thing with the prayer. You're welcome to (politely) pray if you wish. But asking me to be part of that prayer crosses the line.
Here's something else to think about. What's the deal with the circle formation around the food anyway? It strikes me as having its roots in pagan magic. The circle magically traps the food and makes it available for consumption by the trappers. The circle of held hands forms a bond in which the spiritual energy of the participants can flow freely and creates a magical force field to improve the food in the middle. I doubt that, if phrased that way, most modern-day religious people would be comfortable with such a suggestion.
Here is our way: we give toasts to convey wishes of good cheer and friendship. Then we clink our wine glasses together (if you don't drink alcohol, no biggie, we've got plenty of soft stuff) and share freely of our home, our food and drink, and our friendship. If you're down with that, you'll be welcome guests indeed at our house.