In this one they're playing Karuta, a traditional New Year's card matching game. There are several varieties, but the gist of it is that one person draws from a deck that has a letter or clue, and everyone else playing tries to find the card with the matching image or phrase from a separate set spread out on the ground.
Start on the bottom left and go clockwise.
(Mystery Space)
Yomi: "*N*o Chest"
Chiyo: smack "Got it!"
Tomo: "HmHmm!"
Tomo: "What!? I've got a little!"
Yomi: "Very little."
squeeze
Tomo: "Look, I've got enough to squeeze! Give 'em a squeeze! C'mon! C'mon!"
squeeze-squeeze-squeeze
Yomi: "Gaaaah! Just stop doing that! I'm sorry!"
I'm guessing the implication is that Chiyo and Osaka have no chest (hence Osaka's reaction) and Tomo is feeling superior because she has something. I'm not sure why Yomi gets so freaked out at her squeezing her own chest though.