At this present time while we are doing Onpage of any site it is not necessary to put meta keywords as per my knowledge.
What does the word "Onpage" mean? English is my second language that's why don't be confused with such kind of my questions))
most of search engine ignore already meta tag keyword . but you also can fill it to.. that up to you.
The Meta tags are a very important part of the HTML code of your web page. They are read by the search engines but are not displayed as a part of your web page design. Usually they include a concise summary of the web page content and you should include your relevant keywords in them.
According to me meta tag is very very important for site growth and for that have to choose unique keyword for each page and your web page about...
Meta Keyword tags should not be ignored when it comes to optimising the site. Although Google don’t take them into account, I’m fairly confident others will. Not only that but when running things like link building campaigns they tie in very nicely using those key terms and optimising header tags to match also.