no its not like that. Actually the EPOCH has nothing to do with the BATCH_SIZE.
Let me put it this way…
lets say we have 2560 training examples. We choose the BATCH_SIZE of 256, so when we run
for x, t in dataloader_train:
This loop runs for 10 times (2560 examples/256 batch size)
This is one forward pass ove rall the 2560 training examples, also known as 1 EPOCH
Now if we want do repeart the same thing for 50 times, we set put it in another loop, like…
for epoch in range(50):
  for x, t in dataloader_train:

where our EPOCHS = 50
I hope this makes sense  
feel free to ask if you stilll have doubts
Kompai !