FINTRAC's report on Underground Banking Schemes in Canada is exactly 731 KB.
The House of Commons briefing on Local Enterprise Partnerships is also a 731 KB PDF. (731 KB)
Could you please clarify if you are referring to one of these specific documents, the historical Unit 731, or if you need a report digital file sizes and storage units? FINTRAC's report on Underground Banking Schemes in Canada
Once you specify the subject, I can draft a report with the appropriate structure (e.g., Executive Summary, Findings, and Recommendations). Healthy homes standards – what a landlord needs to know the historical Unit 731
If you meant "Unit 731" (the Imperial Japanese Army's biological warfare unit), this is a historical research topic.