* 120 guests: 49 couples and 22 singles
* To be seated at 11-ish tables of 8, 10, 12 people each (by combining 4- and 6-person tables)
* Couples must be seated at the same table
* Plan only needs to say which guests sit at which tables - individual placement at the table will be decided just-in-time by the people putting the name cards down on the day
* It's hard for me to give labels to the guests to give you an idea of who can form a nice table and who can't. It's like, complicated, but I know a good table when I see one.
I made a spreadsheet-based app [1] where I first entered couples and singles into rows and then left blank rows as table separators. On the blank rows I put a "table capacity" number (8, 10 or 12), and on the guest rows I put a formula to compute "remaining table capacity", using conditional formatting to highlight tables where there are too many guests and tables where there are still seats available. By dragging rows around I can quickly rearrange the plan, and the spreadsheet doesn't do much except tell me where the plan is currently "broken" due to overfull tables.
If I compare my requirements with the Better Seater interface, what I'm missing is a way to keep couples together always - I don't want to make a new "group" name for each couple and I don't want to drag twice to move a couple. I haven't tried it with 120 guests, but I'm curious what sort of guestlist size you're aiming for.
[1] https://docs.google.com/spreadsheets/d/1ciib95VBI1YE9KFfPZAp...