Have you ever opened a big file by accident in Atom which caused it to stop responding?
Then this package is for you; prompt-big-file will prompt you to open files that are big.
apm install prompt-big-file
You can configure the minimum size of the file which triggers a warn by overriding the following key in configuration:
prompt-big-file.Threshold
By default this is 1Mb.
See CHANGELOG.md.