Anyway, it should be "I broke them all in the shop." [Use past tense.]
So, all can be several parts of speech. I will give you a dictionary listing that I could think of.
- Being or representing the entire or total number, amount, or quantity: All the windows are open. Deal all the cards. See synonyms at whole.
- Every and any: got into all manner of trouble.
- The whole of one's fortune, resources, or energy; everything one has: The brave defenders gave their all.
- The entire or total number, amount, or quantity; totality: All of us are sick. All that I have is yours.
- Everyone; everything: justice for all.
- Wholly; completely: a room painted all white; directions that were all wrong.
- Each; apiece: a score of five all.
- So much: I am all the better for that experience.
In your sentence, all is an adjective (of quantity) that modifies the object them. Not a noun, nor a pronoun. I think, the all is used for emphasis purpose.
The evidence to that, is that the all can be removed (which means the them is still understandable), and the word all is stating that all of the eggs (the number of them) were broken.
But if you took the all as an noun or a pronoun, it should not be removable from the sentence.
It should be like:
- I broke all in the shop. [Which all?] --> If this were a noun or a pronoun.