I've looked through the source code before but I don't think I saw the CodeGenerator solution. That's a gold mine for the future.
The answer to my question is below. This LPT file is acting upon each entity in the project.
// get the mapping for this entity
EntityMapping mapping = currentProject.GetGroupableModelElementMapping(currentEntity, _executingGenerator.DriverID) as EntityMapping;
Use the mapping in the comments for a generated class
///<summary>
///Methods for fetching, saving and deleting <%= entityClassName %>.
///Database target is <%= mapping.MappedTarget.FullName %>
///</summary>
Sample result in the generated file:
///<summary>
/// Methods for fetching, saving and deleting CustomerEntity.
///Database target is dbo.Customers
///</summary>