TalkTalk Latency Problem

I suffer interminable delay in loading web pages at certain times of day, so I ran the Quality monitor and got graphs I find hard to understand.

BB Q M shows the latest graph I got.

The unusual spiking puzzles me, could they be the result of some sort of throttling by TalkTalk.

Any advice would be welcome

If you were using the connection in those time periods then it is your use causing spikes.

If speed tests are ok once running consider changing dns server as a slow isp one can lead to slow page loads

You're probably right about my use, but I download files OK with no ptoblem.
I changed DNS servers to the google ones (8.8.8.8 & 8.8.4.4) but noticed no change.
What would be a good choice for DNS?

Google is usually a reasonable alternative.

What do the graphs on the speed test at http://www.thinkbroadband.com/speedtest.html show? You can get a good speed sometimes but still see slow web page loads, graphs are designed to help show the situation

The speed test shows no particular problem, once I'm downloading everythings fine, if a bit slow. It's when I attempt to access a new URL that I hit the delay.
That's why I suspect DNS addressing could be the problem.