Final answer:
The as help.class table is available at the beginning of a new SAS session. It's part of the default sashelp library which contains a variety of ready-to-use datasets for reference and educational purposes.
Step-by-step explanation:
The table sashelp.class is available at the beginning of a new SAS session. In SAS, the sashelp library contains a collection of read-only datasets and other resources that are available by default for the user to access for help and reference purposes. The work library is also a default library in SAS, but it is used for temporary storage of datasets and other items created during the session, which are deleted when the session ends. As for user-defined tables like sales or work.newsalesemps, these would only be available if they were explicitly saved in a permanent library or created during the current session.