No harm, no foul. My point is that you didn't indicate from the start that your cell content could contain text that was invalid for a bookmark name, that it could be two or more words separated by spaces or that your really only wanted the first word.
If you really only want the first word then both mine and Paul's code could have been different:
Code:
Sub Demo()
Dim lngIndex As Long
Dim oTbl As Table
For lngIndex = 2 To ActiveDocument.Tables.Count
Set oTbl = ActiveDocument.Tables(lngIndex)
With oTbl
.Range.Bookmarks.Add Trim(.Cell(1, 1).Range.Words(1)), .Range
End With
Next lngIndex
End Sub
Now still, if the first "word" happens to be a number or if there is no first word (empty cell), you will still get and error.