Anti-sag bars are standard on tables longer than 72".  Conference locks are included on large two piece top meeting tables (those longer than 120")
Clic quick connect lock set, small plate lock set, large plate lock set, and fixed plate set are available options 

Clic quick connect table lock

small plate unlocked

small table lock set

anti-sag bar

fixed plate

large plate locked

Clic quick connect table lock set

small plate locked