Variables can be organized into several sections in the spreadsheet view.
The first section is always the Input section, this is not able to be renamed or deleted. Any variables that are in this section will show up in the Dashboard, and are able to be played with (i.e. adjusted) by viewers. If you don't want a variable to appear as an adjustable input, move it out of your model's Inputs section. Note: Model inputs can be in any section of a model!
By default, there is one more section auto-created when you start a new model, named Calculations. However, you can delete or rename that section, add more sections, and reorder sections as you wish.
Easily sum (or avg/min/max...) the variables within a section. Just type sum(Section Name) and Causal will sum all the variables within that group. When variables are added to (or removed from) the group, the function (e.g. sum) will auto-update.
Organise variables under Section Name headers on tables (e.g. Users is the group header in the screenshot below, and the variables underneath are contained in the group)