Depends on the situation. Could mean that or also just not to bother me temporarily. For example, if you are trying to study and someone is trying to get your attention for something unimportant. You don't want them to forget you, but just let you have that time of quiet or alone time. It's not very polite but usually in family like with a brother or sister it's common.

When said as a command it means 'go away'.

Yes