Which options have i got if I have to store lots of files or large data portions with file encryption, access them fast and also have it all-in-one file? Something similar to Sqlite with file encryption and enhanced for large portions of information. Also I want ruby binding.

If you want SQLite, how about we only use SQLite? Because it comes with a BLOB datatype, you could store your encoded data like a BLOB and decrypt it upon retrieval. Simply have Ruby do all of the file encryption and decryption.

I don't know in which you want the important thing(s) to become, however, you can store them in another column should you prefer a different key for each "chunk," or have one key for the whole application (within this situation you might have it configurable on Ruby).