Hello tonyshawjr,
I can help you with this question.
We have a similar question asked here so I am going to quote the response there:
The iCal exporter exports the current view’s events. If you are on month view it will export that month’s events. If you are the upcoming list view, it will export all of the currently visible upcoming events, which by default is the next 10 events.
The easiest solution here would be to change your “Number of events to show per page” in WP Admin > Events > Settings > General. But, that has far reaching implications in that every page in your site which shows upcoming events will display that number of events, not just iCal. If you want a more fine tuned solution then you would want to tab into the iCal WP Query and set the posts_per_page to a different value. You could do that using the filter tribe_events_pre_get_posts.
If you would like some help on this let me know and I can give some more information on this customization.
Thanks