In grammar, a preposition is a word that connects other elements and may indicate location, time, purpose, etc. The Spanish preposition "para" has different meanings and functions according to the context.
In the case of the sentence presented, "para" explains the use or purpose and it is equivalent to "for", this can be seen in the first section "Los platos son para las arepas" that explains "Los platos" (the dishes) are used or should be used as containers for "las arepas" which are a typical food in Latin America. Also, in the second part "las tazas son para el café con leche" the word "para" connecting "las tazas" and "café con leche" show a purpose relationship as the cups (tazas) are containers for the coffee with milk (café con leche).
