Table includes league side initially made up of celebrities (3-4)
I believe the answer is:
all-star
'made up of celebrities' is the definition.
(all-star can mean featuring celebrities)
'table includes league side initially' is the wordplay.
'table' becomes 'altar' (altar is a kind of table).
'includes' indicates putting letters inside.
'initially' indicates taking the first letters.
The first letters of 'league side' is 'ls'.
'altar' enclosing 'ls' is 'ALL-STAR'.
(Other definitions for all-star that I've seen before include "Comprising only top performers" , "Made up of outstanding performers only" , "Composed wholly of top performers" , "Having a well-known cast" , "Entirely comprised of top players/actors" .)