Eurail is a company owned by the national rail companies of Europe and packages and markets rail passes outside of Europe. Eurail is NOT a railroad. You don't travel by Eurail. From Munich to the Swiss border you will be traveling on German Rail, from there to Interlaken by Swiss Rail.
Eurail does have a European rail schedule online at (www.eurail.com/downloads/eurail/eurail_timetable_2008.pdf) but it is nowhere near as complete as the interactive one on Bahn.de; I don't see the Interlaken to Lauterbrunnen connection listed on the Eurail schedule.
Eurail should not be confused with RailEurope, which is a US company owned primarily by French Rail. They resell Eurail passes and also sell a very limited number of tickets (at a markup) for individual train connections in Europe. These are only the major connections (most expensive trains) and they don't show the schedule for trains for which they don't sell tickets. Don't use RailEurope for schedules.
On the Bahn site, you can even find discounted ticket available to purchase online and print out at home.