I'm trying to configure an entry form but I can't find the correct widget.

I need to include an entry form on our website for our trade show exhibitors to enter their information for the show guide.  Each exhibitor has between 1-20 product lines they will be showing at our show.  Each product line falls under one or multiple categories.  I want them to enter the each brand name and select any or all of the categories that particular product falls under.  See attached sheet for what I'm referring to.

I believe the Configurable List widget is the widget that you are looking for. This widget allows your user to add more fields if they want to enter more data. Here's a demo form so you can see it in action: https://form.jotform.com/61654821574965 

Please follow this guide on How to Add a Widget to your Form?. Then to setup the config list widget, you can check out this article: How to Set Up the Configurable List Widget

Regards.