Formatting text so the lines will fit in the available space on the target device are not that easy when it comes to the terminal. Instead of breaking lines by hand you can use the POSIX fold utility and the GNU/BSD fmt command to reflow a text so lines will not exceed a given length.
Learn how to use the paste utility on practical examples to merge text files, and discover a couple of tricks and pitfalls of that command at the same time.
The cut command in Linux allows removing data on each line of a file. Read this tutorial to know how to use it effectively to process text or CSV data file.