1. Eliminate the icons to get more space for the text of item...
.path-calendar .maincalendar .calendarmonth ul li .badge.badge-circle {display: none;}
.path-calendar .maincalendar .calendarmonth ul li .icon {display: none;}
2. Make the font size of text a bit smaller...
.path-calendar .maincalendar .calendarmonth ul li>a {font-size: 0.9em;}
3. Make the item text wrap in cell ala spreadsheet style...
Note that will make your rows different sizes...
.path-calendar .maincalendar .calendarmonth ul li>a {white-space: normal;}
Note that 2 and 3 are actually the same element, so combine them if you want both:
.path-calendar .maincalendar .calendarmonth ul li>a {font-size: 0.9em; white-space: normal;}