What you require is fairly straightforward it is just a matter of looping through the files and pasting the tables into a new document based on one of the files (without its content) e.g. as follows. The only complication is the locked content controls in the document used as template.
Sub GetTables()Dim strFile As String
Dim strPath As String
Dim oDoc As Document, oTarget As Document
Dim oRng As Range
Dim fDialog As FileDialog
Dim i As Integer
Dim oCC As ContentControl
Set fDialog = Application.FileDialog(msoFileDialogFolderPicker)
With fDialog
.TITLE = "Select folder and click OK"
.AllowMultiSelect = False
.InitialView = msoFileDialogViewList
If .Show <> -1 Then
MsgBox "Cancelled By User", , "List Folder Contents"
Exit Sub
End If
strPath = fDialog.SelectedItems.Item(1)
If Right(strPath, 1) <> "\" Then strPath = strPath + "\"
End With
i = 1
strFile = Dir$(strPath & "*.do?")
While strFile <> ""
If i = 1 Then
Set oTarget = Documents.Add(Template:=strPath & strFile)
For Each oCC In oTarget.ContentControls
oCC.LockContentControl = False
Next oCC
oTarget.Range.Text = ""
End If
Set oDoc = Documents.Open(FileName:=strPath & strFile, AddToRecentFiles:=False)
If oDoc.Tables.Count > 3 Then
oDoc.Tables(4).Range.Copy
Set oRng = oTarget.Range
oRng.Collapse 0
oRng.PasteAndFormat wdFormatOriginalFormatting
oRng.End = oTarget.Range.End
oRng.Collapse 0
oRng.Text = vbCr
End If
oDoc.Close SaveChanges:=wdDoNotSaveChanges
i = i + 1
DoEvents
strFile = Dir$()
Wend
lbl_Exit:
Set oDoc = Nothing
Exit Sub
End Sub