In the recommended configuration available HERE, your DB only stores artifact-metadata, build information, and properties. For example, the indexed_archives_entries table stores information required by the class searcher. More information about archive indexing management is available HERE.
As a general rule, a database will occupy approximately 1MB of space for every 100 artifacts, although this may vary based a given type of database being used, the database’s settings, as well as the size and history of its artifacts.
This also assumes that actual binaries are being stored (as we recommend) in the filesystem rather than as BLOBs in the database.
If you don’t need archive indexing, as per the following example, it can be turned off and thereby offer you an opportunity to conserve space:
USE <your database name>
EXEC sp_fulltext_database 'disable'