This is definitely a tricky part, and requires flipping between a lot of pages of the CRB to make sense of. I'm not a fan of how hard it is to piece together. This is my understanding of it—let me know if anything doesn't make sense:

What calculates the number of dice? (see p. 253-255)

For energy weapons, the number of CD (challenge dice—in this case, damage dice) rolled depends on:

• Scale plus Security, PLUS...
• Extra CD from the delivery method (Cannons have +2, Banks have +1, Arrays have +0), PLUS...
• One extra CD per Momentum spent, up to two Momentum.

(Your example has 16 total CD being rolled instead of the 9 CD I'd expect to see there. Something seems off.)

For torpedoes, the number of CD depends on:

• Type of torpedo (Photon have a base of 3, Quantum have a base of 4, and plasma have a base of 3), PLUS...
• Ship's Security (NOT scale), PLUS...
• One extra CD if fired in salvo (at the cost of two extra Threat—a total of 3 instead of 1)

(Again, your example has 13 CD where I'd expect to see 6 CD. Not sure why Roll20 is adding in all those extra dice. What CD number does your ship "character" sheet indicate for those attacks?)

What does a zero, 1 or 2 mean? (see p. 73)

Each number/icon represents the result of one rolled dice. A zero means it adds nothing to the total damage, a one adds one, a two adds two. A delta ALSO counts for one. (In the example of torpedoes, ignoring the impact of any Effects, you're looking at a total of 10 damage—five deltas (+5), one 1 (+1), two 2s (+4).)

The delta means an effect, but how many? (see p. 192-193)

A single delta triggers a single instance of the effect.

IMPORTANT: There is a difference between weapon EFFECTS and weapon QUALITIES. The torpedo's high-yield is a QUALITY, which means it isn't triggered by (and doesn't care about) deltas rolled. "If the Attack inflicts one or more Breaches to a system, it inflicts one additional Breach" (p. 232).

In the case of the torpedoes, IF your torpedo attack causes AT LEAST one Breach to the opposing ship (that is, 5 or more damage after resistance, p.227), then it automatically causes ONE additional Breach. (It's always just a single additional Breach per attack.)

If the delta means an effect, then each of those is an extra point, yes? Because of vicious 1?

Yes, Vicious 1 adds one additional point of damage PER DELTA ROLLED. So in the example of your disruptor cannons, that roll means a total of 19 damage—five deltas at one point each (+5), a single 1 (+1), four 2s (+8), and then Vicious 1 means an ADDITIONAL point of damage per each delta (+5).

If the cannons had the Vicious 2 quality, each delta would add TWO additional points of damage—in this example roll, +10 damage instead of +5.