Creating tabs on the fly is easy in EPiServer, but if you want to be able to put them in an order in edit mode, you can do it as shown below. Create a class, and make sure it has the GroupDefinitions annotation in it:
public static class MyOrgTabs
[Display(Order=123, Description = “My Description..”)]
public const string TeaserText = “TeaserText”
You can place multiple (all) tabs in the newly created class.