1. Go to --> Layout and change size to A4
2. In the Print Dialog Box --> change printer properties to A4
If you already did this and still get prints with huge space on the bottom; try this,
a) Go to --> File
b) Go to --> Options
c) Go to --> Advanced and scroll down...
d) In Print section deselect "Scale content for a4 or 8.5 x11" paper sizes" option and OK....
Now you can print A4 papers without leaving a huge space on the bottom.