As a piece of news it isn't particularly helpful - if you are tall, there's not a lot you can do about it. But also it seems reasonably logical.
It's normal, in this kind of study, to factor out other potential contributory factors, such as being under/over weight, so effectively we are comparing like with like. If two people have the same body mass index and one is taller than the other, then the taller person will have more cells in their body. As cancer is, given similar environmental and genetic background, essentially a statistical disease, the more cells available, the more likely it is that there will be a cancerous cell or cells forming. So it doesn't seem entirely surprising as a result.
The figures show a relatively small difference, and like all such studies it is very difficult to be sure that everything else has been adequately controlled for. There does indeed seem to be a small increase in risk, but we are all subject to a whole host of risks that make us different to other people (diet, hereditary, environment, exercise, smoking etc.) so to worry about a small factor we have no control over seems unnecessary.