Default Miscellaneous Files?

good day to all i was made a factory reset on my samsung galaxy s2 shw-m250s korean version phone yesterday and restore my phone back up using kies but i noticed that my phone storage and usb storage is still full eventhough i only have system apps installed,i check my storage and i find out that still have the data history of my previous apps,my question is,is it ok to delete all data specially in my miscellaneous files?which file is safe to delete?