You need to create a grouping on your tablix by sales agent.
Once you have the grouping follow these steps:
- Right click on the grouping
- Select Group Properties
- Select Page Breaks
- Check the “Between each instance of a group” option
This will split the workbook into tabs by sales agent. You can then name the tab after the sales agent as well by editing the Page Name in the Group properties pane. You will need to use a variable for this.