Final answer:
To display a hidden tab on the ribbon in Excel, access the Excel Options dialog box, navigate to Customize Ribbon, and check the checkbox next to the name of the tab you want to add.
Step-by-step explanation:
To display a hidden tab on the ribbon in Excel, you can follow these steps:
1. Click on the 'File' menu at the top left corner of the screen.
2. In the menu that appears, select 'Options'.
3. The 'Excel Options' dialog box will open. Click on 'Customize Ribbon' on the left side.
4. In the 'Customize the Ribbon' section, you'll see a list of tabs and groups on the right. Find the tab you want to add back to the ribbon.
5. Make sure the checkbox next to the tab's name is checked. If it's not, check it.
6. Click 'OK' at the bottom of the dialog box to save the changes.
Following these steps will display the hidden tab on the ribbon, making it visible and accessible once again.