Again, there are various possible solutions. And behind the scenes, IMHO, this method does the same as Close / Open the file again. But in terms of efficiency it will come down to pushing a button. If opening the file itself is time consuming and slow because of it's size or network connection - maybe this will not help too much.
1. (Depending on your file vesrion/format) If your workbook is in XLSX format - save it as XLSM or XLSB format. The other option that will work is XLS (but compatibility issues may turn up if your Excel version is newer). Basically you need a file format that can store VBA code.
2. (I assume that your Excel is newer than 2003/2007) Enable the Developer tab (if it is hidden), then click on Insert/ ActiveX Controls / Command button (the first in the group). Select a place for your button and place it there.
3. Right click on the newly created button (The design mode button, next to the Insert, must be enabled) and select View code. VBE will pop-up and you will see something like:
VBA Code:
Private Sub CommandButton1_Click()
End Sub
... with your cursor between the lines.
4. add this between the two lines:
VBA Code:
With ThisWorkbook
If .ReadOnly Then .UpdateFromFile
End With
5. Close VBE and save the file.
Assuming that macros are enabled/allowed when the file is opened in read-only mode - clicking the button will bring the file up to date with the last version saved on the disk.