Was this an upgrade from Windows 8 to Windows 10? The 400MB partition is your Windows Recovery Environment (WinRE) that allows you to access startup repair and system restore at boot along with other options. The EFI partition is required for booting. The C: partition as you know is the Windows partition. The other 450MB WinRE partition was added during the upgrade because there was not enough space in the Windows 8 WinRE. The Recovery Partition is for doing a factory reset back to 8. I don't know why Disk Management lists your recovery partition twice.
There is an additional partition that is not detected using disk management called the Microsoft System Reserved Partition.
For the amount of space they take up I would leave the partitions alone.
If this was not an upgrade from 8 to 10 I have no idea why you have two WinRE partitions unless one was added during an upgrade to 8.1.
Edited by JohnC_21, 04 September 2016 - 07:01 PM.