Meaning of 'In current row format, BLOB prefix of 768 bytes is stored inline.'
If your ROW_FORMAT is REDUNDANT/COMPACT, the prefix (upto 768 bytes) of every blob/varchar/text is stored in the index records and remaining bytes are stored in Off-pages. So there is limitation on No of variable length columns in a table (upto 10 can be created in utf8 file format). Whether in DYNAMIC/COMPRESSED row formats, these fields are fully off-paged (prefix 0 byte). So the limitation is relaxed so that upto ~196 Text/Blob can be created in a single table. 

Note : 
Verify whether the table row format is DYNAMIC/COMPRESSED 


  SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESWHERENAME='dbName/tableName'\G


And verify FILE_FORMAT = Barracuda.