You can also ungroup worksheet tabs by clicking any non-grouped tab. To regroup worksheets and tabs, hold "Ctrl," click the tabs for the worksheets you want to group and then release the "Ctrl" key.

Launch Excel. Open the worksheet containing the excess Tab symbols that you want to remove. Open the "Find and Replace" dialog box by pressing "Ctrl-H" on your keyboard. Alternatively, click "Find ...

Click the Yes button. Navigate to excel in HKCU. Right-click on excel > New > Key. Name it as options. Right-click on options > New > DWORD (32-bit) Value. Set the name as moveenterdir.

Regarding Barbara Heard's query on the behaviour of the Tab key in Excel, it is possible that she has activated the Lotus 1-2-3 transition navigation keys which makes Excel work like 1-2-3.