The 3 derived (D) tenses of active optative of athematic verbs in Mycenaean Linear B, as represented by the template verb, didomi:

Here is the chart of the 3 derived (D) tenses of active optative athematic verbs in Mycenaean Linear B, as represented by the template verb, didomi:

athematic-mi-optative-active-verbs-template-didomi-in-mycenaean-linear-b

Note that in the second example sentence in Mycenaean Greek, since the verb didomi is in the future active optative, the Mycenaean Linear B infinitive nikase = to defeat, must also be in the future. This is just another one of those remarkable eminently logical subtleties of ancient Greek, including Mycenaean. 
 
As you can see for yourself, I have been unable to reconstruct a paradigm table for the perfect active optative of athematic verbs in Mycenaean Linear B, as represented by the template verb, didomi. Since I have been unable to find any instances of that tense in any ancient Greek dialect, I am driven to conclude that it could not have existed in Mycenaean Linear B either. This is in contrast with the paradigm table for the active optative tenses of thematic verbs in Mycenaean Linear B, of which there are 4, as attested to here:

thematic-mi-post

Since in this previous post I outlined almost all of the uses of the active optative in ancient Greek, including Mycenaean Linear B, there is no point rehashing these uses here. Simply refer back to the post to glean as full a grasp the multiple uses of the active optative as you can, on the understanding of course that you are already familiar with least Attic grammar.  If you are not versed in ancient Greek grammar, even if you are in modern Greek (in which there is no optative mood), there is really not much point to mastering all of the uses of the active optative in ancient Greek, except in so far as a basic understanding at least may offer you at least some insight into the more subtle and arcane operations of ancient Greek, of which there are plenty, as you might have already imagined by this point.