@Jackk78 The plot sizes displayed on the pool's page are not always accurate. I've read on the forum that a guy with e.g. 5TB on the pool could be mining with much more than that in reality (if I remember, this can be caused by mining on different computers at the same time for the same account).
Also, breaking a big plot into smaller ones will in theory show no clear benefits. Finally, optimizing is a good idea but 30s reading speed is not really a lot. Most of the times, it is recommended to optimize when you take more than 60s to read plots, but of course it won't harm to optimize yours :)
EDIT : last thing to keep in mind is that luck plays a big role, so a guy with less TB can win more blocks than you in a week for example, but in the long run you'll get more coins.