Q) Where work objects will be stored?

A) Work Objects are stored in pc_work table by default. however if you want to store the work objects in a user created table, follow the below mentioned steps.

Create a schema similar to pc_work table. (The best thing is to copy the pc_work schema and modify the table name and constraints name if any)

Change the class group mapping (Data-Admin-DB-Table) to the newly created table.