We do understand that tables and images are essential part of the reports. Thus we do provide the PictureBox and Table item. However there are some limitations when working with HTML, which I will explain here.
Telerik Reporting (TR) is a server solution, which is intended to process and render data, rather than text (be it plain text or richly-formatted text). TR supports several export formats (one of which HTML), but they are all geared towards exporting tabular data and charts, rather than richly-formatted text.
This works in the following way: the reporting engine serves the report content in a predefined format to show it under the specific platform; for example, if you are using TR in a ASP.NET application, it uses a stream to serve HTML to the browser. It is important to note here that the report rendering happens before the content is served to the browser, i.e. the browser has nothing to do with the report rendering. The browser just shows the HTML, which has already been prepared by the report rendering.
If TR is to serve all HTML tags and CSS attributes (be them produced by Microsoft Word, RadEditor for ASP.NET, or RadRichTextBox for Silverlight), we will need to develop a HTML engine which to render this HTML before it hits the client. In other words, we will need to develop a fully functional browser which to process this HTML and CSS and either send it to the client report viewer, or export it to one of the supported formats. Developing a fully functional browser is neither easy nor viable (IE's HTML engine is roughly 10MB, whereas FF's is about 8MB; this is a lot of code). Even Microsoft does not do this in their SQL Reporting Services product.
This is the reason why TR renders a small subset of HTML tags and CSS attributes, all of which have been written by our developers to support the most common text formatting options
We have attached a sample project that illustrates the only possible approach we know of (workaround did not seem like the correct word here): utilizing the WebBrowser control to render HTML to a bitmap. We use an user defined function that does the trick, and a picture box item which displays the generated image (PNG). We're aware that this approach has several shortcomings and is far from perfect, but it seems to work in most cases and in all export formats (which support PictureBox items). One thing to note is that you should set the HTML as value for the browser.DocumentText property, in the example we've used URL from the RadEditor examples to quickly illustrate the approach.
Thank you for the understanding.
Have you tried the new visualization options in Telerik Reporting Q2 2013? You can get them from your account.