Okay, so I've updated the roster entry for Lt Tochi Zai to reflect some "basic information" for each of his symbiont's four previous hosts - Name, gender, occupation, age at death and/or transfer of the symbiont; total time hosting, etc - (this info is found at the end of the Medical History section), and some of the skills/interest/knowledge Tochi's inherited from each of them (this info found in "Special Skills and Ratings").
As pointed out in the roster entry, itself, please note that, at the present point in game time, it is not commonly known that the Trill are a "joined species" (at least from everything I've read, so far), so very few people will likely know about any "previous hosts" - though they may be well aware of the skills/interests/hobbies he's inherited and/or find it odd that he sometimes talks about "remembering" things that happened well before he's physically capable of remembering. If, at any point, you feel the need to use any of this information in your posts, please contact me first so that we can work out the details.
On the other hand, if your character happens to have eclectic tastes in music, for example; and, one day, happens to ask Tochi; "Hey! You're not, by any chance, related to Dirven Zai, are you?" Feel free to do so... Might be an interesting conversation, especially for an aficionado of the Trillian Mandolin.
Thanks, and continue boldly going,
Eol