A Dataset can read your XML file and work with it in memory. For 350 people or records it is perfectly fine.
Relational databases have been over used and promoted where you can do perfectly fine with out it.
Try looking at Sqlite
http://sqlite.org/[
^] if you need a relational database that is embedded and doesn't require an install.
If you feel adventurous take a look at
RaptorDB - the Document Store[
^] for a nosql document database engine.
There are numerous other embedded database engines.