Well, it's a backup. Normally you would not need to use a backup but at the same time it's good to have a backup for something so important as that.
You could delete it, but I don't know if you can add the 9GB free space to a different partition with Minitool Partition Wizard. With the built-in disk management, that's not possible unless the free space is directly located on the right of the partition that you want to add the free space to if I'm not mistaken, which it won't be in this instance.
I would leave all partitions untouched. It does not look like you need the additional space and the 9GB might just end up as free space that can't be added to any partition if Minitool Partition Wizard can't add it to any partition either.