Find tables and views that are not in use at all?
I have used a process from this article by spaghettidba (Gianluca Sartori):

Tracking Table Usage and Identifying Unused Objects

To summarize very briefly:


  
  Search your codebase
  Use the index usage stats DMV
  Use Extended Events to monitor object access, streaming the events with Powershell
  


Gianluca provides many code examples in his article.

There is still a lot of risk 

After collecting data for 3 months. I have renamed unused table to TBD and then finally removed after 6 - 8 months. Good luck.