Epiphany is installed by default for Raspbian and it is supposed to be better optimized for Raspberry Pi. But it seems that Google's Chrome works faster. I also tried firefox, which is called "iceweasel". Ice-weasel seems little better than Epiphany but Chrome seems faster and smoother on scrolling.
You can install Chrome by the command below:
You can also try Firefox:
The screenshot below is Chrome in action: