How Much Area Will a Plug Tray of Chamomile Cover?

What size area will a plug tray of Roman Chamomile cover? I need to plant a 64 square foot area and am unsure of how much to order. Also, I would like to start a border of two or three types of lavender. Approximately how much area will a plug tray cover? Will lavender grow along white pine trees?

If you space each plug 15 cm (6") apart, you can cover about 3 square metres (30 square feet). So you will need two plug trays. Spacing the plants further apart (or closer) will increase (or reduce) the time required to fill in the whole area, but the end result will be the same.
Lavender can be planted single file in the border, 20 cm (8") apart. At this spacing, plugs will take 2-3 years to fill in completely, but by the second year you should already have a modest show of flowers. Lavender does not thrive in shade or in acid soil. White pine may shade the plants too much, and, if the lavenders are planted in the leaf litter zone of the white pine, the soil may be too acidic.