I really like the concept of meeting new people around a dinner table. I do think it is also a more intentional way, or kind of like a cool excuse to get your friends together over dinner and connect your social circles which don't overlap much like they used to in the old days. Although, I do think social events of that kind, happen in more organic way and the spontaneity of meeting new people happens naturally, without an app sometimes.
Given that said, we do live in the 21st century and more people are connecting with each other through apps like this.
My experience of open seat was only one breakfast, it was really awesome in that I got to spend time with people I usually wouldn't have otherwise. I did also see there were one cooking classes, I think this apeals to me more, as it would connect people with similar interests regarding food. I know there are other apps like meet-up where you can connect with people with dimialr interests, but the fact that open seat is focused on foodies that appeals to me a lot.