How do I delete purchased apps from iCloud totally

Purchased apps are not stored in you personal iCloud account. iCloud is is Apple's service for personal file space. Apps are stored in Apple's online App Store and the cloud icon next to them in your purchase history simply indicate they are available for re-download from the App Store.

As for their appearance in your AppleID purchase history, you cannot edit that, so there is no way to delete any purchase item from your purchase history. You can hide apps so they don't show in your purchase history, but you cannot delete them.