To print it on A4 you will have to either reduce the size of the fields, or reduce the number of fields.
When you layout a report, you give it specific dimensions (i.e. Table A is positioned at 100,100), the only time you don't is when you have a matrix and a variable number of columns. If you look at the InteractiveSize property of the report, by default it is set to A4 size and you have to stay within that, if you don't then the excess gets printed on fresh pages (both across and down). So if your report is wider than 21cm (the default InteractiveSize width) then it will overflow onto a new page when printing or rendering to PDF.
So the simple answer is no, you will have to do a bit of work first to make it fit on A4. One thing to check though is some printers will scale the rendered print job if it is bigger than the selected paper size - see if your printer can do this.