Can Runed Halo be used against the zombie tokens created by Field of the Dead?
No, you cannot do that, sorry.
Runed Halo requires you choose a card name. This means your choice is limited to names that exist on actual cards printed for the game.(1) You cannot make an arbitrary choice: for example “Lightning Bolt” is a valid choice, but “Arnold Schwarzenegger” is not because no such card exists (alas).
Field of the Dead creates Zombie tokens, which are simply called “Zombie”.(2) There is no card by that name, so you cannot choose the name “Zombie” for Runed Halo. (Tokens aren't cards, so they don't count towards the pool of card names.)
Choosing the name “Field of the Dead” won't grant you protection from the Zombies it creates. It'll mean you can't be targeted or damaged by Field of the Dead, but it wasn't going to do that anyway.
There is a loophole for tokens that share a name with a card. For example, Goblin Wizardry creates tokens that will be named “Goblin Wizard”. There is also a card by that name: Goblin Wizard. This means it's a name you can choose for Runed Halo, which will then also grant you protection from those tokens because they have that name. You cannot however use this loophole for “Zombie”.

Citation 1:

201.3. If an effect instructs a player to choose a card name, the player must choose the name of a card in the Oracle card reference. (See rule 108.1.) A player may not choose the name of a token unless it’s also the name of a card.

Citation 2:

111.4 A spell or ability that creates a token sets both its name and its subtype(s). If the spell or ability doesn’t specify the name of the token, its name is the same as its subtype(s). A “Goblin Scout creature token,” for example, is named “Goblin Scout” and has the creature subtypes Goblin and Scout. [...]