Each page on Front-End of In-Portal can have unlimited number of content blocks on it. Content blocks are then used to create similar (by design) pages, that only differs by information, displayed on them.
In majority of cases all content blocks entered for a page would be displayed on it at all times. Knowing that I was very surprised to discover, that each content block data is retrieved using a separate database query. So if for example page have 20 content blocks, then extra 20 database queries would be made just to show that page.
I'm proposing to load content of all content blocks for a page with a single database query instead.
Solution
In the "\PageHelper::loadContentBlock", when it's a regular page visit (not through Admin Console frame) load/cache all content blocks of requested page and then use cached data.