Board games! I particularly like 'party games' that are almost activities, easier to get other people to try and they support banter/socialising.
Here are a couple suggestions for playing with friends/family indoors:
Banangrams (2+ competitive scrabble race)
Codenames (2+ word association, or image association if you get the pictures version)
Gloom (2+ card game, good for story-tellers)
Dixit (3+ image association)
Telestrations (2 or 3+ 'illustrations'/'telephone game' - basically Gartic Phone)
Just One (3+ word association)
But maybe you want something that you can do solo...? I have a few I like doing for that.
Illustration. I do it digitally on PC with a drawing tablet, Krita is free art software.
Jigsaws. I have a special jigsaw holder I can slide under the bed so I can take as long as I want and not block the dinner table.
Sleight of hand. Depends on space. I wouldn't twirl my staves inside, but things like poi, fans, card magic, yoyo tricks etc will work in a larger room.
Origami. I recommend getting dedicated origami paper as its not only prettier, its already perfectly square and its a thinner stock designed for folding.