Check out iText; it is a pure Java PDF toolkit which has support for reading data from HTML. I used it recently in a project when I needed to pull content from our CMS and export as PDF files, and it was all rather straightforward. The support for CSS and style tags is pretty limited, but it does render tables without any problems (I never managed to set column width though).
Creating a PDF from HTML goes something like this:
Document doc = new Document(PageSize.A4);
PdfWriter.getInstance(doc, out);
doc.open();
HTMLWorker hw = new HTMLWorker(doc);
hw.parse(new StringReader(html));
doc.close();