Most of the major search engines give little to no weight to the keywords meta tag with regard to search ranking. The main thing with it is to avoid overloading it with too many keywords and risking having a search engine not rank your page due to abuse of the tag.
There is no "bold script" in meta tags. Probably the "someone" was referring to the presence of words within the body of your document that are likely to be search keywords that you would like to find your site. Giving them emphasis by including them within heading tags (H1, H2, etc.), EM, STRONG, B, or I tags may increase their effectiveness to some degree. Again, overdoing this by using the same keyword in multiple places on the page may have a detrimental effect if the search engine thinks you are trying to fool it.
You might want to browse the Search Engines forum further down the list of WebDeveloper.com forums for more information and details on SEO.