The value's are simply Base 64 encoded. For example the subject "VGVzdCBWYWNhdGlvbg==" is B64 for "Test Vacation".
You can use http://www.opinionatedgeek.com/dotnet/tools/Base64Decode/Default.aspx to test that out.
Some additional info:
Some of the key/values aren't very self explanitory.
For instance, daysofweek is an int, which has bits that correspond to a day of the week. 1 is Sunday, 2 is Monday, 4 is Tuesday, 8 is Wednesday, 16 is Thursday, 32 is Friday, 64 is Saturday. So 3 would be Sunday and Monday.
Nthday is an int that works in conjunction with daysofweek. So if daysofweek is 3, and nthday is 2, that will end up with the 2nd Sunday and Monday of the month.
Daily/Weekly/Monthly/Yearly are booleans (only one should be set) for the recurring frequency. Until is the end of the recurrence pattern.
Feel free to inquire about anything else.