If the Media item is not stored as a link, the database size will increase by at least the size of the file being added. 

For example, when adding a JPEG file that is 1.18 MB, the Data space usage of the database is increased by 1.27 MB.

Review How to minimize the increase in database size caused by files stored on the Media tab Link to the file as opposed to saving the file on the Media tab for information on preventing the database size from significantly increasing due to adding new Media items to records.