As Ana said you can do subsets, but you can also define masks of for your 10x10 pixel patches.
Afterwards you can select the drawn geometry in the statistics dialog:
Another option is the pixel extractor (Raster / Export / Export Pixel Values). Here you can define geo-locations and extract a window around them. The statistical computation can then be done in external software like Excel.
And there is the StatisticsOp. It is only available from the command line. It is briefly explained here: A StatisticsOp graph
So you can choos between several options which fits your workflow best.