We cruised on the Enchanted Princess in January with a group of 10. Once I linked them as travel companions in the Medallion App I was able to book for the same table at the same time for all 10 of us.
Maybe calling Princess and having them set it up would be a solution. I think I had to book each night separately as the “book for the same time every night” option seems to have some thyme of bug.
I had chosen a private table for another booking choosing at the same time each evening, and when I checked in the App after booking it was booked as a shared table. I had to book each night separately to ensure a private table.
The App is very glitchy, unreliable and difficult to use.