Translation:Thank you, excuse me.
The subject of the sentence is not the person talking, it is the person you are asking to excuse you. "Thank you, excuse me," is the same as "Thank you, can you excuse me?"
But you may be asking why disculpe and not discupla. The answer is that the sentence is in the imperative mood. The imperative is used for commands or requests. Here you are asking the other person to excuse you. In English where the use of verbs is much simpler, the only difference when the imperative mood is used is that subject pronoun you is not used. Examples: Sit down and take out your pens. Shut up! Halt!
It seems disculpe is used more in the sense of "Please excuse me and pardon my intrusion/allow me to pass/allow me to leave you" etc. It does not seems to mean "I am sorry for my action/I regret doing that/please forgive me". Can any native speakers confirm this? I think what threw me was the seeming similarity to the (admittedly fairly unusual) English verb disculpate, meaning "to find innocent, to free from guilt, to clear from blame, to exculpate". Though I guess this is more like the sense of disculpe.