Use the same getChapterNumber template method you used to number chapters to number table captions.
Out of the box, the PDF plugin doesn’t add chapter, part, or appendix numbers to table titles. Fortunately, it’s easy to add them yourself. You will use the getChapterPrefix template to add chapter numbers to table titles (If you’ve already done the Add chapter, appendix or part number to TOC page numbers exercise, then you already have this template in your plugin, and you can skip Step 1).
You can find this template in the GetChapterPrefix template appendix.