Unfortunately, I don’t think this data is available client-side.
An explanation of chest odds may be in order here, and it’ll get a bit long-winded.
As you know, @Taransworld reports chest odds for all known chests to some reasonable degree of accuracy. It’s a good way to get a sense of what your chances are, though it is not the source of truth for the actual odds of getting any specific troop or other reward from any given key. All the data we have as a community about chest reward chances is informed from the server, which passes to the client at login time a list of all chests and possible rewards from those chests. In the past, this was used to show the “peek” of troops sliding in from the left that would give you a sense of what you could get. Along with those rewards are a set of odds, which are fractions that generally add to 1.
Why exactly the server continues to send this data to the client is a mystery to me, because the client never uses these odds; it doesn’t decide what is in the chests, the server does (for obvious reasons that the client can’t be in control of the player’s inventory). Whatever the reason, @Taransworld scrapes these numbers and posts them on his site, helping players make informed decisions about when and which types of chests to spend their keys and Gems on.
It must be emphasized that we do not know if the server uses these values when rolling. It’s possible that it does, and that the list and odds are just transmitted to the client at login time. This is a rational, reasonable assumption, but it’s not guaranteed, and there’s no way we can know without access to the server source. It’s also possible that there’s a manual step of copying the loot tables from wherever they’re used to roll rewards to wherever they’re transmitted to the client, keeping in mind that it’s possible these are two separate machines or farms doing the work of deciding loot vs. logging in a user. If the process is manual, then the odds he reports (and the ones I posted above) are subject to drift, and the source of truth is unknown to us. If it is not, then we are reporting the actual odds of the rewards for opening chests (distrust of RNG notwithstanding).
However, as far as I can tell, delve chest odds are not being sent to the client. Only those chests for which there is a button in a menu somewhere do have entries, and delve chests are opened through a different path. There’s no need for the client to have these odds anyway, as they’re never shown to the user and only the server should care.
Tl;dr: No, I don’t know the delve chest drop table 