Is it possible to use an Arcade expression to combine attribute values from the attribute tables of different features?

[hannahisreeding]

I'm trying to make a table that is a mash-up and sum of data from the attribute tables of a few of my features. Is this even possible?

For example, one of my attribute tables shows cables, their routes (multiple cables for one route), and their lengths. I would like to make a second table that I would be able to use to sum up the total lengths of the cable for each separate route. The cables in my cable table are split up within the route, so I wouldn't be able to use this attribute table for this data I want. In my ideal table, there would be just one row for each route, which would have various fields of summarized route data from other attribute tables. 

[RichardHowe]

I suspect the tool you want is Summary Statistics 

With this you can assign a "case field" which would be the route name, a "statistics field" which would be length and then a "statistic type" which would be sum. Your output would show you a single row per route, with a count (number of cables) and the total length.

You can add more than one case or statistic field depending on how granular you wish to be.

This tool can also be shortcutted by right-clicking on a field in the attribute tale and selecting "Summarize"