Thank you: bryanvaneeden and RickVerstegen for you andwers.
I have performed more tests with Roles/Privileges and found following facts:
1. Datastore=>Browse Datastore Privilege is enough only for mounting ISO-images from specific Datastore if you have been set a Role with this Privilege on that Datastore for a User
2. Datastore=>Browse Datastore on Datastore + Configuration=>Host=>System Management at least on one Host that accessing that Datastore in case if you want to set permission to Upload files to Datastore. Pay attention to fact: User will not be able to delete files from datastore only able to upload.
Note: This work only in HTML5-version of the client,if you using a FLEX-version, the buttons "Upload File(Folder)" will be grayed out, I think this is a BUG
3. Datastore=>[Browse Datastore,Low Level File Operations] on Datastore + Configuration=>Host=>System Management at least on one Host that accessing that Datastore
Note: Work with HTML5 and FLEX-client
Note: After creating a new Role or changing the permissions of a specific Role, you must delete cookies for your web client address, no matter what client you are using (HTML5 / FLEX), otherwise new permissions will not take effect.