If you need to do compute intensive operations then do:
using CSV
using Tables
robots = [CSV.read(file, Tables.columntable) for file in vector_of_file_names]
and then each robot has a numeric id in this vector (1, 2, 3 etc.), so you can write e.g.
robots[1].x_pos[end]
To get a last x_pos of robot 1.
This is type stable and efficient pattern for your work. In particular it is important to number robots from with 1 and consecutive natural numbers as this will be fastest way to look them up.