my guess would be you have a bunch, 42K, of styles that got indirectly installed..look at all those currency styles..thanks Microsoft....here is a macro that deletes non-standard styles....

Sub StyleKill()

    Dim styT As Style
    Dim intRet As Integer
    Dim Cntr1 As Single, Cntr2 As Single, TotStyles As Single
    
    Application.DisplayStatusBar = True
    Cntr1 = 1
    Cntr2 = 1

    TotStyles = ActiveWorkbook.Styles.Count
    
    For Each styT In ActiveWorkbook.Styles
        DoEvents
        Application.StatusBar = "Working on: " & Cntr1 & " of " & TotStyles & " Deleted: " & Cntr2
        If Not styT.BuiltIn Then
            styT.Delete
            Cntr2 = Cntr2 + 1
        End If
        Cntr1 = Cntr1 + 1
    Next styT
    
    Application.StatusBar = ""

End Sub
I didn't write StyleKill and I would give them credit if I could remember who did....sorry