How can I remove scratches from glass table?
There are commercially available glass polish products that can be helpful and this is an example:

Get such a product and follow the manufacturer's instructions for use.  Keep in mind that polishing scratches can take considerable time since you must remove quite a bit of material over a reasonably large area to get the scratch out.
There are also some products that claim to be able to fill scratches in glass but I've not had any success with any of them.