Budget acts are generally quite extensive. I cannot tell you if some kinds of bills are included more than others. In other areas, it has happened that other budget acts have included fundamental reforms related to other policies. As to whether it is normal or not, I can say that the budget is just one vehicle. It is a legislative process with its own constraints. A budget bill is rarely just a dozen or so pages. They are always quite big and contain provisions that can be important for a government's activities.
On June 16th, 2009. See this statement in context.