The tiny bowls are usually explained as a legacy of the boats: small portions were easier to pass from a rocking boat to customers on the bank without spilling.
A dark, herbal broth thickened with pork or beef blood is ladled over rice noodles with sliced meat, morning glory and crispy pork skin, traditionally served in a small bowl meant for a couple of bites at a time. Diners typically order several rounds at once, since one bowl doesn't go far.
Pad Kra Pao (Thai Basil Stir-Fry)
Moo Ping (Grilled Pork Skewers)
Som Tam (Green Papaya Salad)