I would like to ask is it feasible to define one single entity to map with two tables. If yes, is it a good approach to implement in this way? Thx

Yes you can:

http://www.hibernate.org/hib_docs/annot ... e/#d0e1717

Quote:
You can map a single entity bean to several tables using the @SecondaryTable or @SecondaryTables class level annotations. To express that a column is in a particular table, use the table parameter of @Column or @JoinColumn.

Is this a good aproach? Well it really depends what you are aproaching.

Obviously this kind of entity will cause some extra DML and Joins. But if you have a sound reason to split your data in two tables this is the way to go.l