The rental log shows you the last 15 leads where this rental was included. You can click these leads to go directly to them. The color codes match your status colors for quick reference.
If you want to see more than 15 leads, you can go to the leads page and type “rental: nameofrental” into the keyword box on the left fitler bar. When you see a matching rental name show in the dropdown list, click it.
That will filter all leads such that only those leads including that rental will be shown. You can further filter the leads by changing things like the statuses that you want to see. You can also sort the leads by clicking the column at the top of the lead list. Multiple clicks will change the sort direction. For example, you can click the Date column to sort by date. For additional information on how to filter leads, see the lead filtering article.