Page 148 has all the size modifiers in the chart at the top, but all the ACs for the starships don't appear to have them added in.
Both the Gunnery rules, and the Starship AC rules say to include the modifiers. (Page 149 for Starship AC, and page 162 for Gunnery Rules).
This would lead to the ranges for both being much lower than for regular characters (but would definetly still work). However, It might be easier to only use the chart when fighting between people/vehicles and starships to accomodate the difference. If the combat includes only starships, I would probably just adjust the size mod of -8 to be 0, and then fill out the rest of the table from there.
[Edit/Addition]Looks like someone (you
) mentioned exaclty this in the fleet forum, and the following ship size mod chart was left out:
Ship Sizes Size Category AC/Attack Modifier
1 to 9 tons Tiny +2
10-99 tons Small +1
100-999 tons Medium 0
1000-9999 tons Large -1
10,000-99,999 Huge -2
100,000-999,999 Gargantuan -4
1,000,000+ Colossal -8