As Repaustria said, the test was for 5bar = 50m depth, and obviously it passed.
So that is the pressure at which the test is conducted, the other two figures are the results of that test.
I think the initial strain is the amount that the case compresses (shrinks) when the pressure is first applied. The strain trend then shows the change in that distortion after a period of time (say a minute).
If the trend is stable or negative then that is good - nothing is getting into the case. If the trend shows a positive, then something got into the case during the time the pressure was applied.
I think that's right - but someone else might know better.