Does Oracle 10g Express Edition have enough storage?
@a_horse_with_no_name is correct in recommending the 11g express and you would have more certainty that the project would not run out of room.

You should consider a proviso when you supply the database that you make no representation as to how long it can be used.  Even though you think you will only have ten tables software grows and requests to change or tinker with things never stop. For example:


oh, we have video content now, can you do that?
we need to have lending and borrowing audited
our client interface needs x
we need fast free text searching  


All of these are possible but some are not advisable but they all need more tables and storage.

Also keep in mind that you are more likely to hit the limits for memory depending on how many concurrent users and the connection pooling methods used.
"Other hardware restrictions remain the same with CPU usage capped at one physical core and memory at 1GB".