Source: Tom and Jerry
Tom the Cat is lying on his stomach reading a large book. He is uncontrollably laughing, rolling around, and slapping his leg while reading something funny from the pages, even falling over in hysterics.
This video is used to represent someone finding something incredibly funny, hilarious, or having a laughing fit, usually in response to a joke, a meme, or a ridiculous situation.
The "Tom Laughing While Reading a Book" clip originates from Tom and Jerry and caught on because it captures uncontrollable laughter and amusement in a way that feels both specific and universally applicable. Internet users adopted it as shorthand for moments where the right words exist but the right tone doesn't — so you send the clip instead.
