I believe it is because it doesn’t have a closing tag on the spoiler. Lets see if this works:

Name	Platform	OS	Stage	Link
Artemis (Kmoon)	Kbin, Lemmy (Upcoming)	Android, iOS	Private Beta (Starts End of June)	/c/ArtemisApp@kbin.social
Memmy	Lemmy	Android, iOS	Android Release (Pending Play Store Approval)	/c/memmy@lemmy.ml
Mlem	Lemmy	iOS	Submitted for App Store Review (July 1)	/c/mlemapp@lemmy.ml
Morpha	Lemmy	Android, iOS	Under Development	/c/morpha@vlemmy.net
Thunder (FOSS)	Lemmy	Android, iOS	Alpha Release	[Thunder on GitHub] [Thunder Community]
Beyond	Lemmy	Android, iOS	Under Development	Beyond on Lemmy
Limbo	Lemmy	iOS	TestFlight Beta	Join the Limbo for Lemmy beta on iOS
Jerboa	Lemmy	Android	Released	Jerboa on GitHub
Slide	Lemmy	Android	Under Development (More information coming)	Slide on Lemmy
Sync	Lemmy	Android	Research	/c/syncforlemmy@lemmy.world
Liftoff (FOSS)	Lemmy	Android	Under Development	Liftoff
Connect	Lemmy	Android	Beta	[Connect Release Post], [Connect Community]
Lemon	Lemmy	iOS	Development, Beta in Early July	Lemon Introduction, Lemon Community
Summit	Lemmy	Android	Released	Summit on Google Play, Summit Demo Video

Actually it appears Jerboa, Thunder, and Summit do not support tables inside spoilers, yet.