Group edit mode in Excel allows you to replicate the changes made on active Excel worksheet to many other worksheets.
To enable Group mode, press and hold "Shift" or "Ctrl" key on keyboard and click the Worksheet Tabs you want to include to the Group. Use "Shift" key if you want to select two or mode adjacent worksheets to Group. Use "Ctrl" key, if you want to select two or more non-adjacent worksheets to Group. The word "Group" in Titlebar shows that Group edit mode is enabled.
As you can see from below image, white-colored Tabs are the worksheets in the Group and grey-colored Tabs are the worksheets not in the Group. Active worksheet name color is Green in worksheet Tabs and other sheet names are in black.
The data entered in the active worksheet is replicated to all other worksheets in the Group.
Clicking on any worksheet Tab will exit Group edit mode, if all worksheets in Excel workbook are selected to Group. If all the worksheets are not selected to Group, click on a worksheet Tab which is not in the Group to exit Group edit mode, as shown below.
Another way to exit Excel Group edit mode is by right-clicking on a worksheet Tab which is in the Group and select "Ungroup Sheets".
Note that the changes made on active worksheet will be replicated to all worksheets in the Group. Keep in mind that there is a possibility of unwanted data changes in other worksheets.