The volume of tea leaves which can be packed into the mini-pack packaging varies according to the size of the leaf and constituents of the blend, if applicable. Mini packs of loose tea contain between 6-8 cups worth of tea, depending on the tea itself. In weight terms, that's about 18-20g of loose tea.
Mini packs of pyramid teabags contain 4 pyramids.
(Note: Mini-packs state a minimum weight of 5g on the label, but the contents obviously weigh much more).