Non-key readmultis are very similar to standard readmulti operations, the only difference being that they return all rows of a table rather than those which match a partial key. They operate by executing SQL statements which do not have a where clause; i.e. they operate on all rows on a table.
Non-key operations, as the name suggests, do not take a key parameter. They operate by executing SQL statements which do not have a where clause; i.e. they operate on all rows on a table.
For a non-key read operation, there should be a single row on the table - this type of operation is typically used to read a value from a control table which contains a single record.
There is no such thing as a non-key insert operation since insert operations do not require a key parameter.