Sure Erika, you can connect a tablet via HDMI to your TV and play back the incoming signal.
Depending on the tablet there are better ways of doing this which simply involve streaming the signal wirelessly to your television.
iPads can be streamed to an Apple TV (or any other Apple device) via Airplay.
Samsung and other Android tablets can stream to newer Samsung TV's or home theater PC's or a Google TV set top box etc.
or just hook it up via HDMI and go that route.
Lots of options, the only bottleneck would be your internet connection.
I would actually find out what kind of streaming you're thinking of doing first. Is this Youtube we're talking about or one of those "other" kind of sites that let you stream things? The former is easy with either an iOS or Android tablet. The later sometimes means that you have to use flash which means that you're stuck using an Android based tablet as they're the only ones that support flash.
Android does not support Flash anymore. You can still find it, but it is not available by default.
As for streaming, honestly the best way to do it is to commit to one vendor. I'm an Android user, but Apple hooks everything in properly. A few friends have the Apple Airport router, iPad's and AppleTV's. Together those are able to stream stuff to/from tablets and TV's. For example, one friend loves to find crazy Youtube videos on his iPad and will then press a button on the screen and voila! it is playing on his plasma. It just works.
Myself? I prefer complicated with a chance of being broken, because I don't buy into the whole Apple thing, but I give credit where it is due.
ETA: the streaming happens over wireless, sort of. I'll verify the actual function, but that's how I've seen it work. No cables required.
80 bucks will get you Netflix/Youtube/Radio all you need is wifi and an HDMI cable. It will also playback anything you put on your PC provided you can download and install PS3MediaPlayer or some other DLNA server software.
Probably the cheapest way to get Netflix on your TV right now, well at least the cheapest I've found.