Well, make sure both Excel books are open.
Then select in the first workbook all the worksheets you wish to copy (you can select multiple worksheets by pressing the CTRL key while clicking their tabs. Or if there are many worksheets to copy, click the first worksheet's tab, then scroll to the last worksheet and select it while holding down the Shift key, that will select all of them).
Now right click on one of the selected worksheet tabs, and choose "move or copy...". A dialog box will appear.
From the drop down menu choose the name of the target workbook.
Click OK.
Thats it! The selected worksheets have been copied to the target workbook.
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