Business card page layout help

I am making a 12 month calendar (2 sided, 6months per side). It will be a wallet size business card (2x3.5"). I have the calendar made in excel and I want to print as many as possible on a 8.5x11 page. I will print the first 6 months, turn it around and print the next six months to make it double sided.
I need to somehow shrink or format the calendar to get 10 calendars/page (2 acroos the width, 5 down the page). Does anyone have any ideas on what might be the easiest way to do this. I will attach the calendar if anyone wants to see it.