Dine and DashG 10

Dine and Dash G10:
Merge 3 Food Rooms

This achievement can be unlocked by placing 3 un-upgraded Diners next to each other on the same floor. When you place up to 3 of the same room next to each other of the same upgrade level, they will merge into 1 big room. When you merge 3, you will get this achievement.