a couple a months ago, I download Dr. Thomas L. Constable's bible notes from his website. his bible notes are in PDF. is there any I can make my own module of his bible for my personal library in L3/L4?
You would need to use Personal Book builder in Logos 4. The input must be in Microsoft Word format, so you'd first have to convert the .pdf to MS Word format. You would probably want to reformat the headings and text in some way after converting it to a MS Word file and before creating your Personal Book. Before you do this you should be sure that you are permitted to save the file in another format on your computer.
BTW: You do know his notes are available in Logos format? That would save you a lot of work and almost certainly produce a better result.
http://www.logos.com/product/4466/tom-constables-expository-bible-study-notes
While you might be able to convert a pdf file through MS Word to a personal book file for use in L3/L4 you may have to invest considerable time in reformatting the notes depending on how you do the pdf to MS Word conversion (copy and paste or with various OCR software for example). (7000 pages involved if you intend to convert ALL of the notes)
You would still have a resource missing all the tagging that Galaxie built into the Logos format of the same resources.
I would only recommend the route you propose for copyright free, public domain works which are not already available in Logos format and not currently on pre-pub or community pricing offers.
If you intend only to read the notes without added functionality then why not use them as the pdf format intended in a pdf reader ?
Otherwise as suggested above, $39.95 for 7000 pages of notes per http://www.logos.com/product/4466/tom-constables-expository-bible-study-notes - probably a better use of your time than having to proof read (even a quick scan through) and tweek the formatting in a pdf to MS Word conversion of that magnitude and with a personal book version you still miss out on all the resource tagging put in to the Logos version, AND you miss out on free upgrades to this resource. Logos seem to be gradually moving through "third party" resources such as this to eliminate typographical errors and improve tagging functionality to align with the capabilities of the new software engines.