In the old days, this was never an issue: one file, one table. Simple. Now you have choices
There are many threads here, that discuss the pros, and cons
I have never seen a performance difference. It's all about convenience. It's just easier to develop with everything in one place
if you have one table you know will grow huge, it might pay to make that a separate file ( and you can change your mind later )
> how does one determine or make the asessment if that might make the database too bloated or affect performance?
Sounds like you need to be searching for 'data separation model'
Myself, I put 'all' tables in a single b_data file , exept for docs/images in a separate file, and occasionally LUT data in a dedicated file when there is periodic updates e.g goverment PBS benefits; so I can import the latest yearly/whenever schedule into a copy, and email the update so the user can drag and drop replace/upload...