Sub ブックを初期化して空にする()
    Dim ws As Worksheet
    Dim lo As ListObject
    Dim i As Long

    Application.ScreenUpdating = False
    Application.DisplayAlerts = False

    On Error Resume Next

    '===== ListObject（QueryTableを含む）を削除 =====
    For Each ws In ThisWorkbook.Worksheets

        For i = ws.ListObjects.Count To 1 Step -1

            Set lo = ws.ListObjects(i)

            ' 外部データに接続されたテーブルのみ対象
            If Not lo.QueryTable Is Nothing Then
                lo.Delete
            End If

        Next i

    Next ws

    '===== WorkbookConnection を削除 =====
    For i = ThisWorkbook.Connections.Count To 1 Step -1
        ThisWorkbook.Connections(i).Delete
    Next i

    '===== Queries を削除 =====
    For i = ThisWorkbook.Queries.Count To 1 Step -1
        ThisWorkbook.Queries(i).Delete
    Next i

    On Error GoTo 0

    Application.DisplayAlerts = True
    Application.ScreenUpdating = True

End Sub