hi and welcome…!
VRDB database creates a backup of some important for the system files so in the case ur pc gets infected by a virus and affects ur system files,u can restore them and make ur pc work again…don’t worry about the size of files coz is very small…u won’t notice any big difference in ur HDD’S size…enable it again and let it “generate” coz its a rly important feature that only avast has(other AV products have something similar though(System backup etc)
i hope i helped u…have a nice day 