Where should I enter fees paid for temporary market space (craft sales, space in retail stores, etc)?

You can claim these expenses as Line 9270 – Other expenses.

This line is under work from home expenses for covid, is that correct? The market fees are regarding my self employed income. 

No, it's also on the T2125 Statement of Business or Professional Activities. And also on the T776 Rental Statement too. 🙂