No, not before the wedding meal,, I've been to a wedding where they came round with the cake in slices during the evening, well after the meal.
Traditionally, the cake [a royal iced fruit cake] was sliced, wrapped and distributed to the guests after the wedding day [maybe a week or so].
I've been married a long time and we waited until coming home from Honeymoon [2 weeks]. All the cake portions were wrapped, labelled and I added a thank you cards for presents e.t.c.
These days wedding cakes are made of sponge & fondant, which is more perishable, so giving it out on the day / night makes more sense to have it fresh.