I remember enjoying these as a child without understanding any of the subtext or satire:
Jonathan Swift: Gulliver's Travels
Umberto Eco: The Name of the Rose
Bohumil Hrabal: Cutting it Short
Antal Szerb: The Pendragon Legend
Jonathan Swift: Gulliver's Travels
Umberto Eco: The Name of the Rose
Bohumil Hrabal: Cutting it Short
Antal Szerb: The Pendragon Legend
A good portion of the book are philosophical discussions, which would be IMHO very boring and not understandable for small children.
The magic of novels like Svejk or Little Prince is that those extra layers are mostly implied, emergent, they're not written out explicitly and thus don't bore out the young readers.