How do I read this table presented in the book "Modern Openings"? Specifically, what do the rows, columns and the dashed lines represent? Finally, there are also little letters like
(a) which are probably related to explanations that come up later in the book.
The columns represent the main variants which continues the movements at the head of the table. White's moves are followed by Black's in the same column. The numbers to the left of the table are the movement numbers.
The ellipsis are there to group the variants. For example, after 3 Nf3 g5 you can play 4 h4 or 4 Bc4. If White chooses the continuation 4 Bc4 he will find that Black's most sensitive responses are 4 ... Bg7 or 4 ... g4.
The lower case letters in parentheses are notes, which follow the table, which show alternative lines considered less important or that show possible pitfalls. The mark in the last move of each column refers to the model game. The evaluation of the final position is expressed with words instead of symbols such as = (equal) or + / = (the target is slightly better).
Each column corresponds to a line of play.
A row corresponds to a move; the dashed line indicates where columns diverge from previous columns.
For example, column 3 gives the line 1 e4 e5 2 f4 exf4 3. Nf3 g5 4. h4 g4 5. Ne5 d6 6. Nxg4 Nf6 ...
The letters are footnotes which should be at the bottom of the page (sometimes they overflow to the next page). They give comments on the move, most frequently showing why an alternative move does not work out.