Telerik Reporting supports printing only of whole pages. Therefore you will have to adjust the page size so that it fits your needs. In case a group of items takes half a page you might consider using A5 for example instead of A4. You can also reduce the bottom and top margins to minimum. Also please have in mind that the printer applies some margins too.
Have you tried the new visualization options in Telerik Reporting Q1 2013? You can get them from your account.