Stat scrolls are permenant gains. They come in +5, +10, +15, +20 and +25. Right now you should have a maxium of 230 stat points. "Eating" (dbl clicking it) a stat scroll increases the max by that amount (see last sentence for exceptions). The Max you can get stats to is 255. Also it is good to note they do not stack. Can't eat +5's to get to 255 . So if you eat a +10 and then get a +15 you will only gain 5 more available stat points.

Vepl