SQLite Filesize still not changing after drop table

• I have a SQLite 4MB database.
• I used the drop table command name; and I threw it. I checked in SQlite Manager that there is no more table name.
• However, I checked the file size, it is still 4 MB, the same.
• I use NotePade, open the database, I see that the old content that I inserted is still there.

Did I do something wrong with the drop table command? or does SQLite keep old data and file size the same?

Thanks for the help.