You can freely add or remove tabs from a tabs panel.
To do so:
1. Select the tabs panel you want to add a tab to.
2. Click Add Tabs located on the tabs lower settings window.
This will create a new blank tab, you can use the Duplicate Tab option in the settings panel to add a new tab with the same content as the current tab.
3. To remove a tab click the Remove icon (Trash Bun) next to the tab name in the top settings menu.