Google Adsense Sensitive Categories
According to a note from Google Adsense website, starting last month, they rolled out new beta inventory of ads that might be bothering to some people, which is "Social Casino Games". This includes poker, bingo, lotteries among other games. If you are like me, do not like showing such ads even with the slightest possibility that they could be seen by the ads engine as relevant to some of your content, you can opt out of them. Simply by clicking "Allow and block ads" at the top, then choosing "Sensitive Categories", and block the categories you do not like. (see the image below)