In a PDF book, usually I put my 10-inch Tablet landscape to have a better visual.

Then, I zoom to discard left and right (usually) blank margins of the page I'm reading, to have the text as big as possible.

In this situation, it would be great if I could lock the horizontal scroll so when I scroll down to read the next page, the page itself do not move horizontally.

It is really hard to scroll down (or up) making a perfect straight movement with the finger, so the page always move horizontally during a vertical scroll and I have to center it again every time.