steps to create ebook friendly pdf file from LaTEX

Recommended pdf file was with a5 papersize, 0.5 cm margins, and 14 point doublespaced text. In order to achieve that, had to follow these,
https://www.overleaf.com/learn/latex/Questions/How_do_I_adjust_the_font_size%3F
https://tex.stackexchange.com/questions/402009/exam-with-18pt-main-font

in my case, by adding the line
\usepackage[14pt]{extsizes}

and later
\documentclass[
14pt
etc.

And afterwards, needed to resize some figures to make them fit in the smaller page size, and also make text tiny in tables to make them fit.
https://tex.stackexchange.com/questions/374757/how-to-make-font-size-small-in-a-tabular-environment

\centering
\tiny
\begin{tabular}