Specifying the Bean’s Container
Size 
Use
Use this procedure to specify the initial size of the EJB Container when the bean is loaded. The container size denotes the size of the table of active enterprise bean instances.
You can specify the container size deployment property for stateful session beans and entity beans.
The InitialSize pool property specifies the number of passive enterprise bean instances in the pool. Although there is no relation between the container size and the initial size of the pool, typically, the sizes of these two properties are close.
You can specify both pool properties and container size only for entity beans.
Procedure
...
1. Open the ejb-j2ee-engine.xml.
2. From the Enterprise Beans tab, choose the corresponding tree structure according to the type of your enterprise bean ® your enterprise bean.
3. In the Container size field in the right-hand pane, specify the bean’s container size.
See also:
Specifying the Initial Cache Size of the Persistence Manager