Here is an extract I have to translate from a book, can you pelase check tenses and give your suggestions?

Thank you.

They sat at the table.

-Have I interrupted your reading?

-Nnno... you haven't. It doesn't matter...

-Are you reading?

He showed her a front page of the book that he kept holding in his hand, marking with his index finger the page he had been reading.

-I haven't read it. Is it good?

- I don't know yet. It's a required reading/tutorial.

-Oh, required reading! I see. I graduated just before the war started and I know, required reading is always something you would never otherwise read.

-Excellent definition!

They laughed.
Tenses are fine. Other cosmetics:

the front page
was holding
It's required reading
I know required reading

Muchas graciasEmotion: smile