yeaa...and to flash something small received via bluetooth i needed it as i download mods to my pc then send it to phone via bt...sooo u saved my 2 worthy minutes of moving .zip via file manager hehe
That's part of the new CWM Nandroid backup structure.
It makes bulk of it's backups to blobs and update to include changes in subsequent backups, saves space and reduces nand write cycles on multiple backups. Don't delete it when deleting old backups, instead just delete the dated backup folders and the blobs folder will get trimmed by CWM when running future backups. If you delete blobs the individual backups would fail.