Sub КопиЛастШит()
    Dim wb1 As Workbook
    Dim wb2 As Workbook
    
    On Error Resume Next
        Set wb1 = Workbooks("Книга1.xlsx")
        Set wb2 = Workbooks("Книга2.xlsx")
        If Err <> 0 Then
            MsgBox "Нет книги.", vbInformation
            Exit Sub
        End If
    On Error GoTo 0
    
    wb2.Activate
    With wb1
        .Sheets(.Sheets.Count).UsedRange.Copy ActiveSheet.Cells(1, 1)
    End With
    
End Sub