The number of internal links per page tends not to matter much from a PageRank perspective.
- Fewer links per page will pass more PageRank per link.
- Also, pages on your site will receive fewer links from other pages on your site.
There is a fixed amount of PageRank available to your site. You can distribute it to your pages via internal links. The number of links you use per page doesn’t change the amount that is available, not will it change the amount of PageRank that most of your pages end up getting from external links.
If there is some particular page that you want to rank better, it is possible to adjust PageRank going to it from internal links and help it rank better. Removing other links from the pages linking to it would be one way of doing so. However, it is usually easier to create more links to that page from additional pages that hadn’t linked to it before.
It is also tempting to try to remove internal links to pages that don’t matter for SEO. Why would you link and pass PageRank to pages that you don’t want to rank? For example, if you have pages in robots.txt, will it help the rest of your site to remove the links to them? From my experiments, it appears not to. I’ve never been able to increase rankings to my site as a whole by “preserving” PageRank by removing links to pages that Google doesn’t index.