It means giving a small token of appreciation, often when more is desired or expected. After the team's hard work, the manager threw them a bone with a pizza lunch.
Pro Tip 2/3
Not Literal
The phrase is metaphorical and does not involve real bones. To keep the interns motivated, the company occasionally throws them a bone like a shout-out at meetings.
Pro Tip 3/3
Possibly Patronizing
It can sometimes suggest that the reward is insignificant and may not be received positively. The year-end bonus felt like the CEO was just throwing the employees a bone.