The individual tabs in the control are stored in a Tabs collection. Tabs can be added/edited/removed in design time by clicking the elipse button in the Tabs property in the property inspector to invoke the Tabs editor.
Tabs can also be added/edited/removed at runtime by using the methods attached to the control's Tabs collection.
Example:
VB.NET
'Create a new instance of the dbi tab page object
Dim newTabPage As New Dbi.WinControl.Tabs.TabPage
'Set the properties of the new tab page
newTabPage.Title = "New Tab Page"
'Add the new tab page to the Tabs collection in the control
Me.DbicTabs1.Tabs.Add(newTabPage)
C#
//Create a new instance of the dbi tab page object
Dbi.WinControl.Tabs.TabPage newTabPage = new Dbi.WinControl.Tabs.TabPage();
//Set the properties of the new tab page
newTabPage.Title = "New Tab Page";
//Add the new tab page to the Tabs collection in the control
this.DbicTabs1.Tabs.Add(newTabPage);