Some years ago in what was then called the "Theocratic Ministry School" the first talk or "Instruction talk" was spent reviewing the material from the "All Scripture (si)" book which contained 66 chapters discussing a particular bible book. I seem to recall there may have been several weeks spent on each chapter.
Yes, the first talk covered a few consecutive chapters in a sequential bible book, and the number 2 talk was a bible reading of a small, select few verses of one of those chapters, in the book, covered by the number 1 talk. This was done weekly, taking (i believe) about 2 1/2 years or so to cover the entire bible. You were supposed to read the entire bible chapter selections in your personal preparation for the meeting. So only 15-20 minutes were devoted to an average of 5 or so chapters of the bible, per week. Enough time to skim, but not nearly enough time to delve in.
I was at these meetings where the Watchtower Society spent one hour each week showing you how to present the Watchtower and Awake magazines but only spent a few short years and spent a short amount of time (a half-hour) teaching (skimming) through the 66 books in the Bible in a question and answer session. I think that this book was the only material that the Society ever printed that actually came close to Bible teaching.
Now, we know that the Watchtower Society is just a real estate and book publishing corporation.