In the last roadmap tell us that new composer soon will have the posibility to include relational table data without write the RT script and do that directly from the UI. I think that this must include the posibility to select a relational table query or create it directly from the email composer. Today you must to create the query, check if it is ok and then "call" into the template. In the future will be great if you can create a new one, check if it is ok, and then, show you tools like "add a table", drag and drop RT fields or just leave a field into the text, url or wathever. (I use a lor personalization from RT with just a single value like in SMS or in Mobile messages)