Why do you consider tables to be safer?
Well if the graph is small scale two people can come with two different answers and both be right. The answer also depends on the quality of your eye and it's different to get lost amid hundreds of lines.
You just have to look for a number in the table and sometimes do the simple math.
I would say it's like comparing analog and digital...
Theoretically analog can be more precise but for some reason everything went to digital...