Clue: Register egg being eaten by tragic figure, along with large bap (9,4)
Answer: ELECTORAL ROLL
Explanation: Definition: Register
 O(a circle, a rounded object resembling an egg) **contained in**(being eaten by) ELECTRA(the mythological main character in Greek tragedies by Sophocles, Euripides and others) **plus**(along with) L(abbrev. for "large") + ROLL(bap/a large round flattish bread roll).
Defn: … of eligible voters in a district or constituency.