Non-Operating Expenses are expenses that are a result of secondary activities of companies. (Primary activities are those that are related to core businesses.)
This is, necesarilly, a broad line. Note that it could include both secondary businesses and financing and investing activities. Examples of items that are included are rental income, interest income (or loss), earnings (or losses) from nonconsolidated subsidiaries, and foreign exchange gains or losses.
This line is netted out; it could potentially be non-operating income. If the line is positive, it is income. A negative result is an expense.