Customers need space to reach their tables, and your staff needs space to access the tables too! If a customer or one of your waiters has their route blocked, it's up to you to move any objects that might be in the way.
All you have to do is make some space between your tables and it will work fine. Please take a look at the video below for reference.
https://www.youtube.com/watch?v=TKy6VkDdqwc