What is Dell OpenManage Ubuntu Repository? Do we need to install for Ubuntu? enter link description here
It is a repository to install Dell OpenManage, a software designed to manage deployments of dell servers. It's usually only used on big IT shops.
You shouldn't install it unless you have a rack with some hundreds of dell servers in the backyard ;).
You would want to use this if you are running a DELL PowerEdge Server, and need to monitor it over a network. You wouldn't need this unless you were using a server more then likely, but you could install this via CLI to work on a DELL Desktop with RAID [Haven't tested the second scenario].
The installation procedure for Ubuntu is not for the novice since it requires some tweaking and is used for monitoring production servers used in business settings [e.g. rack servers in Data Centers].