Efficient reading of technical texts or books means that you read much faster and at the same time you can absorb more than with normal reading. Of course, efficient reading does not mean reading the whole text from front to back, but in several passes, where the aim is to first get an overview by first reading the abstract, introduction, table of contents, the blurb or the summaries at the beginning of each chapter. In some cases, it can also be useful to take a closer look at the index or especially the illustrations, if there are any.
Extra tip: Sometimes it is also helpful to search for the text or the book on the Internet, because there may be summaries or, in the case of books, reviews.
After the overview, you ask yourself what your goals are for reading, so you ask questions of the text or formulate questions in writing that the text should answer. In this step, you also break down the entire learning material into edible bites that you can work through in one or two study sessions. During actual learning, one can quickly skim these individual sections, i.e., read the text quickly and superficially and mark possible relevant sections. In doing so, you should make sure that you really only mark the important parts of the text for further processing, whereby less is always more. Now the thorough reading follows section by section, i.e. one reads the marked sections slowly and thoroughly, whereby one should always have a technical dictionary at hand in order to immediately look up unknown terms. It is also important to make the first notes here, perhaps in the form of a mind map or by creating questions and answers on index cards. With this method, it is essential to read selectively and actively process what you have read.