Savetable with P5

p5.js
2

so possibly empty files are not allowed?
need minimum a table structure to make a header line

https://editor.p5js.org/kll/sketches/Ie48wONx

but usually start the other way, from reading a file
-a- create in online editor a subdirectory
/assets/
-b- create inthere a new file ‘Memory.csv’
edit it manually with 2 lines minimum,
one header line
one data line

(or upload the file from you computer )

and in your code just use
https://p5js.org/reference/#/p5/loadTable

function preload() {
  table = loadTable('assets/Memory.csv', 'csv', 'header');
}