Who is the Principle applicant?
If you are then your spouse's employment records are irrelevant, unless it is Canadian. Therefore, you should say they have no work experience under employment history and enter it in the personal history section (post - ITA) where no evidence is required.
If they are the principle applicant follow these instructions:
"if the applicant is self-employed, articles of incorporation or other evidence of business ownership, evidence of self-employment income and documentation from third-party individuals indicating the service provided along with payment details (self-declared main duties or affidavits are not acceptable proof of self-employed work experience)."