The information you're looking for is found here, on Loot Tables:
https://minecraft.fandom.com/wiki/Loot_table
And here, on Predicates:
https://minecraft.fandom.com/wiki/Predicate
So specifically, in this case, the Table Bonus is the probability parameters being set for the drops in regards to the Fortune enchantment.
Survives explosion sets the probability of getting the block when an explosion occurs within the built in radius. If this isn't set, it's always successful.
Not sure what else you need to know, but I'm sure you can find it on those two pages and whatever other links on them.