If you are doing this from an application (VB.Net or C++ or php or whatever), then you load the data in chunks.

[Here is a PHP example][1] from Oracle.

[Here is a C++ example][2] from Stack Overflow.

[Here is a C#.Net example][3] from Code Project.

If you're doing this from scripts, check out [SQL*Loader][4].

    LOAD DATA 
    INFILE example13.dat 
    INTO TABLE EXAMPLE13 
    FIELDS TERMINATED BY ',' 
    ( EMPNO INTEGER EXTERNAL, 
    ENAME CHAR, 
    JOB CHAR, 
    MGR INTEGER EXTERNAL, 
    SAL DECIMAL EXTERNAL, 
    COMM DECIMAL EXTERNAL, 
    DEPTNO INTEGER EXTERNAL, 
    RES_FILE FILLER CHAR(60), 
    "IMAGE" BFILE(CONSTANT "ORDIMGDIR", RES_FILE) 
    )

 
If one of these examples isn't the right programming language or doesn't help you, let me know and I'll try to find you one for that language.

  [1]: https://docs.oracle.com/cd/E17781_01/appdev.112/e18555/ch_twelve_blobs.htm#TDPPH185
  [2]: http://stackoverflow.com/questions/12781553/odbc-write-blob-example-oracle-c
  [3]: https://www.codeproject.com/Articles/48619/Reading-and-Writing-BLOB-Data-to-Microsoft-SQL-or
  [4]: https://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:392618837633