Many 0.1 -6 mb + disk images on running "diskutil list"under "Recovery HD". Is it normal? There are about 10 of 7 of them and are images extremely small.Is it the requirement of system or the leftovers after formatting disks having other OSes?
Yes - the recovery HD layers many components to make a bootable system so I would call that normal / intended.

Since you are booting to a write restricted environment on an OS that typically wants to write log files, cache databases, system settings - those are likely created to be easily discardable without modifying the OS substantially for booting on Recovery HD as opposed to booting from a volume as normal.