singular

   nom          ὁ    δεσπότ    ης   
gen    τοῦ    δεσπότ    ου
dat          τῷ  δεσπότ    ῃ
acc    τὸν   δεσπότ    ην
voc  ὦ   δέσποτ    α
  

plural

   nom          οἱ   δεσπότ    αι   
gen          τῶν   δεσποτ   ῶν
dat    τοῖς   δεσπότ    αις
acc    τοὺς   δεσπότ    ας
voc    ὦ   δεσπότ    αι
  
 
 
  Notes  
  • The genitive plural is always emphasized with a circumflex (sound drawn out, voice going up and then down again) on the last syllable.
    For all 1st declension nouns, masculine as well as feminine.
     
  • Accentuation
    All endings are long, except for the vocative singular and the nominative/vocative plural.
    In the singular, the vocative always ends in α.
    And it behaves a little strangely: Sometimes, like here, it moves to the antepenult (if the penult is short) , sometimes, although it stays put, it changes to a circumflex (if the penult is long), e.g.
    ὁ πολίτης, τοῦ πολίτου, ὦ πολῖτα

    Your book will indicate by a macron that the penult is long, I won't do that, because some Unicode fonts have trouble in producing a legible macron (in combination with other diacritics), Arial Unicode MS for instance, and others display little boxes or @ instead. So, no macrons on my pages, except very occasionally. Sorry.