This works for me in my test, delete all tables in the activedocument with only empty cells at all:
Code:
Sub Test()
Dim oTbl As Table
For Each oTbl In ActiveDocument.Tables
If Len(Replace(Replace(oTbl.Range.Text, Chr(7), ""), Chr(13), "")) = 0 Then oTbl.Delete
Next
End Sub
Backup original files before test, test before use, use at your own.