Private Sub CommandButton1_Click()
    Dim strBook2 As String
    Dim wb As Workbook
    
    With Application.FileDialog(msoFileDialogOpen)
        .Show
        strBook2 = .SelectedItems( 1 )
    End With
    
    With Application
        .ScreenUpdating = False
        Set wb = .Workbooks.Open(strBook2)
        With ThisWorkbook.Worksheets("Лист1")
            .Cells.Clear
            wb.Worksheets("Лист1").Cells.Copy Destination:=.Range("A1")
        End With
        wb.Close
        .ScreenUpdating = True
    End With
End Sub