What does the word "brakers" mean?
"... from six till twelve, when he has lunch." - Why "when" is used here?

Gordon Higgins, the author of 'Brakers' and 'The Sword' 1)__ at five o'clock every morning and 2)__ a shower. He 3)__ breakfast at five thirty, then he 4)__ to his study and 5)__ from six till twelve, when he has lunch. Gordon usually 7)__ back to his study to work from one till five, but sometimes he 8)__ his publisher to talk about his new books...
Taken from Enterprise 1 by Virginia Evans

Question

What does the word "brakers" mean?
"... from six till twelve, when he has lunch." - Why "when" is used here?

Gordon Higgins, the author of 'Brakers' and 'The Sword' 1)__ at five o'clock every morning and 2)__ a shower. He 3)__ breakfast at five thirty, then he 4)__  to his study and 5)__  from six till twelve, when he has lunch. Gordon usually 7)__ back to his study to work from one till five, but sometimes he 8)__ his publisher to talk about his new books... 
Taken from Enterprise 1 by Virginia Evans

Answer

I have no idea what it means. I expect the author means something by it. If one reads the book one may find out.

Or maybe it will always remain a mystery!

Answer

A brake is a mechanism which stops a machine, such as the brake/brakes on a car. 'Brakers' - I presume - means people who use brakes. This is supposedly the title of a book, so it can mean anything which the author wants it to mean.

As far as I can tell, this author, and his two books, were invented by the writer of this grammar exercise. So you really don't need to worry about it.

Answer

It is a VERY odd word.

"Breakers" with an "e" is an ordinary word. It has several meanings.

1) "Breakers" can mean ocean waves whose crests "break" as they approach the shore. "The Breakers" is a popular name for seaside homes, hotels, and cottages--including a museum-sized marble mansion built at the seaside in the 1890s by a millionaire.

2) "Breakers" can mean urban youths "breakdancing."

3) "Breakers" can mean college students vacationing on their "spring break" between semesters.

Answer

The only definition I can find for "braker" is "a shipbuilder". I've never headed the word and maybe the author created it for his book.

"When" here means "at this time". So he had his lunch at twelve.