To make appointment printouts fit on A5 paper you may need to make some changes to the appointment print style in the practice settings.
Appointment printing on paper
Go to Settings > Diary > Appointments > Appointment Printing
When you set up your printer to print, leave the Appointment Card Printer NOT ticked.
Put in the standard text and data tags.
When you come to print, use the correct size paper in the print preview.
You may need to select More Settings
If you have A5 paper, change the paper size to A5
Appointment Card Printer
Set Appointment card printer to Yes
This opens up a series of additional options.
You should now be able to print correctly to your appointment card printer.