By default a single dashboard can contain up to six components (views, charts etc.).
For CRM on-premise, this can be altered via a Powershell command (https://msdn.microsoft.com/en-us/library/gg334200.aspx).
For CRM Online there is no access to the application server to perform this command. Are Microsoft Support willing to make this change on behalf of a CRM Customer, or are all Online customers stuck with up to six components?