1) Nintendo Switch with Yoshi's Crafted World (easiest game for kids), buy an extra controller because I think it only comes with 1... earliest age for this would be about 3, 3.5, and would need some in-game assistance from their older sibling (which the game provides mechanisms for)
2) iPads with games, including coloring games ... even a 2 year old can enjoy iPad games
3) Netflix cartoons
4) Amazon Prime cartoons
5) Kinetic sand (https://www.amazon.com/Only-Kinetic-Sand-Folding-2lbs/dp/B01... plus an extra http://amazon.com/Kinetic-Sand-Pounds-Beach-Packaging/dp/B01..., possibly doubling both for 2 kids)
6) MegaBlocks (https://www.amazon.com/Mega-Bloks-80-Piece-Building-Classic/...) I would buy 2x per kid to ensure they have plenty to build with
7) small dry erase boards and colored dry erase markers
8) YouTube Premium (remove the ads so they don't interrupt their cartoons)... for example, they might like Blippi https://www.youtube.com/user/BlippiVideos
I'm not saying little kids should play video games all the time, but it does give them something entertaining to focus their attention on.