I want to know that can't I make different auto meta template for different products in different category. For example I've two categories sofa and table now I want a different meta for sofa products and different meta for table product.
In Magento admin panel Catalog->Categories -> Manage Categories-> Select a category.
There will be option to provide the page title, meta keyword and description for each and every category
DYNAMIC METAs for products, you should Override
head.phtml template for
PRODUCT VIEW pages.
See here for : How to override head.phtml
Then apply your custom logic for METAs in that file