How do i add something to the end of the line using sed?

[maltiger]

Man page for sed: https://www.lightnetics.com/post/3334

Sample file used, called tabfile.

hamsterparty	donkeyparty	horseparty	badgerparty

Use this:

$ sed 's/$/ Mind the gap/' tabfile

Result:
hamsterparty donkeyparty horseparty badgerparty Mind the gap