Yeah, 17" is a bit cumbersome if you ask me. But to your question...
The Radeon HD 7340 is actually a very slow iGPU (integrated graphics). It is much slower than the Intel HD 3000 iGPU in Intel's previous Sandy Bridge generation CPUs. The Intel HD 4000 in Intel's current Ivy Bridge CPUs will simply crush the Radeon HD 7340. See link below for some game benchmarks.
For example, in FIFA 2013 the Intel HD 3000's performance is 166% better than the Radeon HD 7340. That's an extreme exception though since the Intel HD 3000's performance is generally better by double digits, not triple digits. I test the Intel HD 3000 on my laptop (Lenovo Y470) with Mass Effect 3 (not a very demanding game) and while it is quite playable it is not as enjoyable as using the nVidia GT 550m GPU in the laptop. The Intel 3000's performance in ME 3 is 64% better than the Radeon HD 7340. In other words, the game would have been unplayable using a Radeon HD 7340.
Based on Google search, it seems that specific Toshiba model is only sold in the UK. Therefore, I assume you live in the UK. I recommend the following 15.6" HP laptop selling for £399.99. It has the Radeon HD 7500G graphic core which is more powerful than the Intel HD 3000, but a little less powerful than the Intel HD 4000.