Last tested: May 2020
No.
When you first make a project, you are prompted to generate LookML for it based on a database connection. You won't get this option a second time, mostly because we assume you've made changes to the model file since then.
You can, however, create a new view from a database table by clicking the plus sign ("Add Files") in the LookML IDE and choosing "Create View From Table".
This content is subject to limited support.
This is time-consuming in case big tables are added to a dataset in BQ.
I hope in the future updates of looker there will be an option to automatically add new tables to the existing project.