update timestamp if change_event for all column in row

Try this. This will update Column A with the current date/time based on any changes in columns B:J

Private Sub Worksheet_Change(ByVal Target As Range)
    Row = Target.Row
    Col = Target.Column
    If Col >= 2 And Col <= 10 Then
        Cells(Row, 1) = Now()
    End If
End Sub