Cry with me
With 5 kids, 10 and under, the chances that everyone is happy at once is lower than you'd wish.
With everyone's personal preferences about temperature, sound level, who they want to sit next to, and who has permission to look at who, it can be very challenging to have a quiet meal time.
Cross that with a belief that kids should be allowed to cry when they're sad, that expressing emotions is a good thing to do, and we're left with a conundrum. Domino theory implies that when one kid starts wailing, it's merely a matter of time until the stoplight hits red, as the decibels go through the roof.
So... when one kid starts at it, here's a quick trick that might work a few times:
Say “You're sooooo sad!” (Start by acknowledging their emotions. According to the text books, this is all you need to do ;–)
Then say “It's too loud here for us to cry, but I want to take care of you. I'm going to carry you to your room, and hold you while you cry. When you're all done, we can go back to the table.”
You aren't ostracizing or punishing them. You're loving on them, validating their right to feel strongly and express it, but also letting them know their impact on the rest of the family.
If it ends up that the crying is taking too long in their room, you can let them know “I'm really hungry right now, I'm going to go eat, and I can come back when I'm done. If you are all done crying first, come down and join us!”
Make them feel wanted and loved, and chances are they will be ready to join soooner rather than later.