The QTableView just displays the data contained in its model. You have to work with this model to retrieve the data. You must also define how you want to store the values. For instance:
model = tableView.model()
data = []
for row in range(model.rowCount()):
data.append([])
for column in range(model.columnCount()):
index = model.index(row, column)
# We suppose data are strings
data[row].append(str(model.data(index).toString()))