How to delete more than one iCloud contact at once!
Step one: Open iCloud in your desktop browser, then click Contacts. You need to have synced your iOS device to an iCloud account in order to follow this tutorial.
Step two: Hold down the Ctrl key (or Command key if you’re a Mac user), and click the first contact you want to delete, then select the rest.
Step three: Release the Ctrl or Command key, and your chosen contacts will remain selected but there is no longer an Edit or Delete option.
Step four: In the lower-left corner of the screen, click the gear icon to bring up the Actions menu. Click Delete and confirm the deletions.
Once completed, iCloud should sync with your iPhone or iPad address book to make the same deletions. This method is much faster than removing contacts one at a time.