If you have too much space, you may have entered extra line spaces (or carriage returns) after a text entry. Open the Edit box and remove the extra space, just as you would with a word processor.

If you still have trouble with spacing, you can try adjusting the margins a bit to force more (or less) text onto each page.

Click the Margins button and adjust the margins in PX, or pixels.
HINT:
1/8 inch =   9 PX
1/4 inch = 18 PX
1/2 inch = 36 PX
1 inch    = 72 PX