Whenever you export any report from Salesforce, it always has a few lines of footer with some information, as shown in the following screenshot:
If you do not want such footers in exported reports, you can perform the following steps to stop this footer:
Navigate to Setup | Build | Customize | Reports and Dashboards.
Go to the user interface section and select the Export Reports without Footers checkbox, as shown in the following screenshot:
Click on Save.