Tabular is just a table maker. It will not insert anything into the game or font or do anything like that. Tables are purely a hacker concept to aid hackers moving between programs/dealing with custom encodings and nothing that exists in the game.
To add them to the game most people would either hack the font/text decoding to respond to the characters you want there (the hard way, unless it is nftr in which case it is easier but still annoying) or would overwrite an existing character in the font and tell the game to call that instead*.
*general idea is if the font has say { and } in it then you are never going to need those in a normal game, overwrite those with say ñ and Ñ and that way when you call what the game originally used for { you will instead get ñ displayed. This is nicer when working in Japanese games where you have thousands of characters and thus can add all the accented characters you want without issue, however most modern European language using games will have enough pointless punctuation that you can make it work. Also if you are running short on space then you might not need all of those accented characters.