Here is the full list of all 17 Tavern Master achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Finish all of the researches
Do an event for the king and the queen
Reach the last reward from quests
Have all 6 historical paintings
Have all food on 5 stars
Unlock the fourth floor
Have 30 employees
Have 100.000 coins at once
Have a 5 star hotel room
Unlock the third floor
Have a successful adventure which had less than 30% chance to succeed
Have one food dish on 5 stars
Have a bar with all barrels purchased and filled
Unlock the second floor
Build a hotel room
Unlock the kitchen
Level up an employee to level 10