I use the excellent Name Manager add-in to, erm, manage the named ranges in my workbooks, including all those pesky ones like the example you give that are automatically created by Excel when autofiltering etc. which aren't normally exposed.
It allows filtering of names by type, location, scope etc. and generally knocks the awful built-in dialog into next week.
Edit: If installing an add-in is out of the question then adding the following code in a standard module will allow you to loop through the names in the workbook and delete the offending items.
Sub deleteNamedRanges()
Dim n As Name
Dim a As Variant
For Each n In ThisWorkbook.Names
a = MsgBox("Do you want to delete the following name?:" & vbCrLf & vbCrLf & n.Name & " (" & n.RefersTo & ")", vbYesNo, "Delete ranges")
If a = vbYes Then
n.Delete
End If
Next n
End Sub
If there are a great many names then you should be able to modify this to suit your needs.