Database size

I want to know whether there is a specific database space or for every activity in the free version ( Desktop Version ) or open depending on the hard disk space of the computer
because i have now 2 business , first one now 4 MB , Second one 13 MB
i can attach any file more ? or Delete old one to upload new file ?

There are no limitation on the size of the business file

Each business has its own file

Not sure what you mean by the last two questions

you can have any number of business files in Manager.