Given that you’re on a relatively outdated Julia version (I would recommend moving to 1.4.2) you might also be on an old CSV version, so I can’t promise that this works, but when using CSV you should use the limit keyword, not rows. See the docs here, you probably want:
DataFrame(CSV.File("input_file", delim = ' ', limit = 10))
You might also want to consider header=false as additional kwarg given that you say you want to get a 10x2 array from the first 10 rows (implying there’s no header to be read in).