A Portrait of the artist as a young man

Hello

I am portuguese an I´m reading this book for the first time and I have some doubts.

In the first chapters of the book , during the christmas dinner when Sthephen is with his father, mum , Mr, Casey, Mrs. Riordan and Uncle Charles, ther is this excerpt from the text:
" Simon, said Mrs Dedalus, you haven't given Mrs Riordan any sauce. "

Is Mr. Dedalus is talking to himself ?

During the dinner there´s another dialogue:
" —Let them leave politics alone, said Mr Casey, or the people may leave their church alone.

—You hear? said Dante, turning to Mrs Dedalus.

—Mr Casey! Simon! said Mrs Dedalus, let it end now. "

When Mr. Dedalus says " Simon" he is talking again to himself ?

I would like your Help.

Thank you

Bruno