How to Change Column Width for All Word Tables at Once

Solution 1:

You could use a VBA macro to resize every table.

Press ALT+F11 in Word and insert the macro under Project » ThisDocument.
Execute the code with F5

Sub resizeTables()    
  For Each Table In ActiveDocument.Tables
    On Error Resume Next
    Table.Columns(1).Width = 200
    Table.Columns(2).Width = 300
    On Error GoTo 0
  Next    
End Sub

• Columns(2) represents the column 2 in every table
• The value Width = 300 is your desired width in pixel. Change it to your needs
• If your table has less columns than your VBA macro, you will get an exception. For this, I added On Error Resume Next to ignore errors and On Error GoTo 0 to stop this error handling