You have set your system to create an error report, in the form of a 'minidump', when it encounters a critical error and has to restart.
The idea of the minidump is that the contents will help you diagnose the cause of the error. However, unless you have a Master degree in computer gobbledygook, it will be meaningless to mere mortals like us.
It is safe to delete, if you wish.
You can change how your compute behaves when it encounters a critical error by right-clicking My Computer, choosing Properties > Advanced > Startup & Recovery.
You can also right-click My Computer, choose Manage, and view the System Event files to get more meaningful messages about system errors.