Why would this leader resist my suggestion?

if you felt compelled to pray for them, then by all means pray for them yourself, but i see no point, right in the middle of lunch, of stopping everyone from eating and praying because you feel it was appropriate. besides, no point in praying for the dead (let the dead bury the dead), that leaves only the families needing prayer, and i am quite sure that there are several people in your immediate life, and theirs, that need a more personal prayer... to me, the kind of prayer you mentioned is a feel good prayer and has no value