Sub juxtaposition()

a = Array(1, 2, 3, 4, 5, 6, 7, 8, 9, 0)

b = Array("A", "B", "C", "D", "E", "", "", "", "", "")


For i = 2 To 1000
Set myCell = Cells(i, 5)
Set My2Cell = myCell.Offset(0, 1)

If myCell.Value = a(0) Then
My2Cell.Value = b(0)
End If

If myCell.Value = a(1) Then
My2Cell.Value = b(1)
End If

If myCell.Value = a(2) Then
My2Cell.Value = b(2)
End If

If myCell.Value = a(3) Then
My2Cell.Value = b(3)
End If

If myCell.Value = a(4) Then
My2Cell.Value = b(4)
End If

If myCell.Value = a(5) Then
My2Cell.Value = b(5)
End If

Next i

End Sub

Sub test()
    Application.ScreenUpdating = False
    Application.Calculation = xlCalculationManual
    lr = 2
    With Sheets(1)
        For i = 2 To Cells(Rows.Count, 1).End(xlUp).Row
            For k = 2 To Cells(Rows.Count, 2).End(xlUp).Row
                If Cells(k, "B") <> " " Then
                   Cells(i, "A").Copy Cells(lr, "E")
                   Cells(k, "B").Copy Cells(lr, "F")
                   lr = lr + 1
                End If
            Next
         Next
    End With
    Application.Calculation = xlCalculationAutomatic
    Application.ScreenUpdating = True
End Sub