If Allshare isn't available in the app store, then look for iMediashare or any other DNLA capable app. I'm assuming the TV is a "Smart" one, and connects somehow to your home network. Now look for a Media Link app/option on the TV. Run the DNLA app on your tablet, then run the Media Link app on the TV. The TV should see the tablet and any other media share devices that are on yor network. Pick either local or web content from your tablet, and the tablet should be able to send it to the TV.
I do this with my LG Smart TV. I'm working on the assumtion that all the Smart TVs are somewhat similar, despite being from different companies.
Good luck. It's a joy when it works.