The slope is 2. Here's why:
Take any two pairs on the table (in this case, I took 6,11 and 2, 3). Plug the two pairs in with the point-slope equation, or:
y2 - y1/x2 - x1
Which would look like this:
3 - 11/2 - 6
Now, follow the order of operations to solve:
3 - 11 = -8
2 - 6 = -4
-8/-4 = 2
And the result of dividing -8 by -4 is 2, which is our slope :)
