As far as I know, there is no built-in library in the J2ME APIs for rendering HTML. For example,
ReqWireless WebViewer uses a
servlet which first fetches web pages, translates them into a "simplified" HTML document, and then delivers the simplified HTML to the device where the WebViewer client code renders the HTML "manually". I'm afraid you'll have to do something similar (write code for rendering HTML yourself).
(Obviously I'll be glad to hear about any existing libraries for doing this!)