How to read Capacitance Table?
How are you measuring the capacitance? It doesn't take much to pick up 10's of pF of stray capacitance, and measuring single digit pF capacitors isn't easy.

The green body 30pF cap has a range of 6.2pF (maximum that you can expect the lowest capacitance to be) to 30pF +50/-10% (range you can expect the maximum to be, or 27pF to 45pF).

So it does not appear to be suitable to get your minimum capacitance required, especially if you have to account for some layout and other stray capacitance in your circuit. You might consider re-design of your circuit so that the minimum capacitance required isn't so low.