With 9 players and one DM/GM/ST, you each get 6 minutes to talk/move per hour, assuming everyone gets the exact same amount of time.
So if you play monthly for 4 hours per session, you get 24 minutes.

This probably only works for combat-heavy railroads or mega-dungeons.

Not my cup of tea, but if it’s what you want, I hope you find a table that suits you.