Münsingen is a German town near Stuttgart. It was also the site of a German military training camp from 1895 until 2004. Although the training camp is now closed, the barracks are still there, and you can now ride your bike around the natural areas on former training camp grounds. This photo was taken in 1904 or earlier.
I might have assumed that the gentlemen would remove their helmets for lunch, but apparently not.
Happy to have arrived after an unpleasant two-hour journey! Heartfelt greetings ...illegible.
Here's a close-up of the table on the right.
The card is addressed to her Excellency Frau von Hugo, presumably the wife of Major von Hugo, the German Military Attaché to Paris. He may also have been the sender of the card.