The form asked for the amount OWED. Look at the instructions above the section to be filled out.
Look at the timeline. July. That was right when Cruz had defeated Dewhurst (so this isn't the form to the FEC). When did Cruz get the loan, how much of it, and does that mean he had already paid it back so that he only owed between 100 to 200 thousand on it?
This document appears to, indeed, just be a financial disclosure form he probably had to fill out after beating Dewhurst. It isn't a disclosure that he received a massive loan to pay for his campaign. It's just listing his personal liabilities.