In the story, the Rainbow Inn is like the town's only hotel, which serves like a multipurpose room: Its lower level has a bar (tavern, public house or "pub") in which the townspeople go to idle a couple of hours of the day or night. It is also perhaps the only place in Raveloe that serves as a common point of interest, so everyone from every walk of life comes in to meet with their equals. This is why they celebrated different events in the inn. Finally it served as shelter to some of the people who visited or were commuting from and to Raveloe. This is why Eppie offered Silas a place to stay until he recovered.
So, if you are making a text to world connection and that is the purpose of the question, then you can say that the Rainbow Inn is like a modern day hotel in a small town, or better yet, like a boarding house with a pub in which people could do activities, spend the night, or have a drink with their fellow townsfolk.