Currently the software does not allow multiple fonts in a single data based text region.
Though the the layout you mentioned is possible to set up.
Instead of trying to use one region and fit that information on there, you can just create separate regions for Company 1, Company 2 and the visitors for each company.
1. Create 1 text region and connect it to the excel sheet.
2. Copy the region and paste 3 copies.
3. Select the first region and change it Company 1. (This one will display Company 1)
4. Select the second region and Change it to Company 1 Visitors. (This will contain all the visitors from company 1)
5. Select the third region and change it to Company 2. (This will display Company 2)
6. Select the fourth region and change it to Company 2 visitors. (This will display Company 2 visitors)
This will give you the ability to change the font for each section.
This how the regions could possibly be setup:
The final outcome:
How the example excel sheet is setup: