It's said to be a traditional Shangdong snack --- "jiao gua bing", but I've heard that many Beijingers enjoy it, too and they call it "hu ta zi".

Is this called "vegetable marrow" in English?

In Chinese we call it "jiao gua" or "xi hu lu".
1.two mid-sized vegetable marrows.
2.some salt.
3. half tea cup of flour.
4.an egg
5. some oil
I. shred the marrows
II. put the salt into shredded marrows
III. when there appears some marrow juice, put in flour and egg, blend them into kind of paste
IV. cook it in the way of making pancakes