A tablet has two important advantages over a laptop/desktop: portability and instant-on (although apparently this is also available on a desktop platform now). These allow you to jump straight into a task the moment you have in mind to do it, wherever you are. That goes well with an order capturing use case. The person tasked to do the order entry is no longer bound to a desk and is free to perform other tasks that require him/her to move about.
Having dabbled with Lazarus for a month, i can conclude that Lazarus is a viable RAD platform. Here are some of the features of Lazarus/Free Pascal that make application development easy (in comparison to the Java platform):