"attributing tags to content" isn't the way I'd phrase it, but it sounds like you want to tag DOM content with keywords for single-page filtering.
This could be accomplished in many ways, but the simplest is to use an HTML data- attribute (like <div data-keywords="cloud database">) on your items. This allows you to use simple CSS rules to hide/show content. Any web developer should know how to do this.
There's nothing specific to Marketo here. It's basic single-page HTML/JS stuff -- Marketo LPs can do anything a single HTML page can, with no limitations.
Thanks so much Sanford, most helpful!