[u]I may have found the answer to my question.[/u] A paragraph with an example was found about 50 pages further into the book. Here is copy of the text:
To lift the heavier plant, you would have to exert a force of 100 newtons. So the amount of work you do would be 100 newtons × 0.5 meter, or 50 N•m.
My first idea was correct, that the dot represented the multiplication dot. I then questioned that and continued looking and found that it could also refer to a chemical period (dots 1,6). The N•m expression appears numerous times but not in a chemical context (this text is also formatted using Chemical Notation).
I feel confident that the multiplication dot is the correct format.