In booking timeline view, if there is a single booking that has no table assigned to it, it's table will be suggested automatically by the system.
All booking with suggested table will be displayed in transparent as shown below.
If you would like to lock all the tables to the suggested table, click on the Lock in button located at the right bottom.
Click Yes to proceed.
You will now see that the "Customer" booking block is opaque, meaning the booking is fixed to table 07.
Other booking will not be able to book the same table at the same time.