Sub Offset()
'Modified 8/3/2018 11:37 PM EDT
Application.ScreenUpdating = False
Dim i As Long
Dim Lastrow As Long
Lastrow = Cells(Rows.Count, "A").End(xlUp).Row
For i = 1 To Lastrow
If Cells(i, 1).Value = "Tom" Then Cells(i, 1).Offset(, 3).Value = "Jones"
Next
Application.ScreenUpdating = True
End Sub