This trophy is for hunting 10 mini monsters, there aren't many events that outright just hand over these crowns. There was one earlier in 2019 for the Great Jagras but for the most part you need to rely on either luck thru investigations or the more guaranteed crown event quests.
https://monsterhunterworld.wiki.fextralife.com/Event+QuestsThese appear in yellow as "Higher Crown chance"
There are 30 in the game and you need 10 (Certain monsters are excluded), these quests below cover 22/30. Leaving you in potentially amazing shape for even the all crowns trophy, except for the fact you must rely on luck for the remaining 8 (or get lucky and they do something like last years wild Mini/large Deviljho event)
These are the quest to look out for
Deep Green Blues: Great Jagras + Pukei-Pukei + Tobi-Kadachi + Anjanath + Rathalos
Effluvial Opera : Great Girros + Odogaron + Radobaan + Bazelgeuse
Rock N' Roll Recess: Dodogama + Lavasioth + Uragaan + Azure Rathalos
Wildspire Bolero: Kulu-Ya-Ku + Barroth + Diablos + Jyuratodus + Rathian
Coral Waltz: Hunt Tzitzi-Ya-Ku + Paolumu + Pink Rathian + Legiana