Вывод в консоли : "Петров 0.0 Сидоров 0.0" 
public static void main(String @NotNull [] args) throws IOException {
        BufferedReader fr = new BufferedReader(new FileReader("D:\\OneDrive\\Рабочий стол\\f.txt"));
        Map<String, Double> map = new TreeMap<>();

        while (fr.ready()) {
            String key = fr.readLine().split(" ")[0];

            if (!map.containsKey(key)) {
                map.put(key, 0d);
            } else {
                double value = Double.parseDouble(fr.readLine().split(" ")[1]);
                map.put(key, map.get(key) + value);
            }
        }
        for (Map.Entry<String, Double> pair : map.entrySet()) {
            String k = pair.getKey();
            double v = pair.getValue();

            System.out.println(k + " " + v);
        }
    }
}