I am NOT a communal person, I don't even like sharing my food with my own party .... but we love Biergarten. We have had all kinds of combinations of numbers, we have had friendly people we conversed with the entire meal, folks who politely said hello then did their own thing, people who literally stared at their plates and pretended we were not there AND even the folks who said they did not want to sit with "us" .... one couple left the restaurant as communal was not okay and the restaurant refused their request.
One trip was four of us closest to band, a couple on other end and in between two solos who sat across from each other. We had one of our best meals ever there with everyone contributing great conversation and the one solo had lived in Germany many years so the CMs were hanging around talking as well.
If it is somewhere you want to eat, you don't mind sitting close to strangers and prepared for all kinds of personalities - go for it. The only time I might be upset is if they tried to sit me with a singular large party or a party with lots of small children. I'd likely make my requests on check in to be with like table mates.
NOTE: We did go with a party of 7, during the holidays when crowded and they did not put a single in our extra chair. My hope is that is something they are aware would be highly awkward.
Honestly the seating here is awkward for a solo diner. It's two tables of four. We're a party of 3 and were seated with a solo diner. We tried to be friendly but he was very quiet and it was just odd all around. The restaurant staff also put our DD's high chair next to him so it started off awkward because we had to shift everything around. The party of four just ignored all of us lol. We've gone a few times and never have much luck with table mates so I only like this restaurant with a large party now.
While structurally it may be two tables, it is really a table setup for a party of 8. There could be 6 and 2 ... 5 and 3 ... 4 and 4 .... 4 and 2 and 2 .... all different combinations. It is not considered two tables of four.
If you go as an odd numbered party you can assume that one of you will sit across from a stranger.