Error after installing and enabling "Rooms-Drupal Booking for Hotels, B&B and Vacations" and dependent modules After installing and enabling "Rooms-Drupal Booking for Hotels, B&amp;B and Vacations" and dependent modules, I get this error when I try to go to the content menu. Does anybody have anything to fix this issue? I had to download multiple modules since they were dependent. 

If you don't, can you recommend me a better solution for Room Reservations?
The dr8 part of your table name seems suspicious ... since you're using Drupal 7, while that dr8 might refer to something related to Drupal 8.

If that's not what is causing your problem, and as per the last phrase in your question ("... a better solution for Room Reservations ..."), then have a look at these alternative modules (with a stable release) for managing reservations in D7 (quotes are from their project pages):


Availability Calendars.


  ... allows you to add an availability calendar to entities. Example use cases are tourist accommodation, e.g. bed and breakfast, holiday homes or self catered apartments, and car or motor bike rental.
  
  An availability calendar shows your customers at what dates your accommodation is still available and at what dates it is already booked.

Simple Reservation.


  ... provides a simple and easy way to reserve items which can be created by the administrator. Examples for it's usage can be hotel rooms, boats, cars, airplanes, basically anything you can think of which can be reserved by one individual.
  
  The module provides the possibility to create reservations for other users (dependend on the permissions), and provides also restrictions in the maximum number of reservations a user can make and a maximum time a reservation can be made in advance.
  
  There is NO support for payment, booking and what ever one could imagine beyond the pure and simple reservation, and it is also NOT intended to create more than this simple functionality.

MERCI.


  ... can extend any content type into a list of unique reservable items (like studios) or buckets of interchangeable items (like DV cameras). We followed the approach used by Organic Groups, Feed API, and Scheduler and added MERCI's configuration to the Edit tab of those content types.

Resource Conflict.


  ... allows for users to book resources for use during events. For example, a student can book a microscope for use within their lab.



I've ordered my recommended shortlist above by number of reported installs. Though that is often a good first indicator, it should not be used as the only criterium to pick a module.