It's quite easy!
I had the same problem but a very bigger dent. Our friends Bobpuls and liten told me how to fix it.
Just buy some synthetic wood. It's similar to silicone but when it gets dry, it's harder as wood.
Spread in the dent until it covers all the hole. Don't be afraid to put to much of the product. Then let it dry for about 24h.
After that with a very thin sandpaper, sandpaper the dry product until it's smooth and just as flat as the rest of the blade.
This is important!
Before glue the rubbers again you have to clean very well the blade because of all the dust the sandpaper will make. I, personally used duct tape to clean it. Just stick duct tape all over the entire surface of both sides of the blade and then, gently pull it of. All dust particles should be glued to the tape.
It´s all in this thread
http://www.tabletennisdaily.co.uk/forum/showthread.php?11853-Help-me-saving-a-relic-(blade)
As you can see, it's easy! If i can everyone can!