displaying grid of images in jupyter notebook

Your idea of using IPython.core.display with HTML is imho the best approach for that kind of task. matplotlib is super inefficient when it comes to plotting such a huge number of images (especially if you have them as URLs).
There's a small package I built based on that concept - it's called ipyplot

import ipyplot

images = data1['url'].values
labels = data1['id'].values

ipyplot.plot_images(images, labels, img_width=150)

You would get a plot similar to this:

The best way to show a grid of images in the Jupyter notebook is probably using matplotlib to create the grid, since you can also plot images on matplotlib axes using imshow.

I'm using a 3x165 grid, since that is 495 exactly. Feel free to mess around with that to change the dimensions of the grid.

import urllib
f, axarr = plt.subplots(3, 165)
curr_row = 0
for index, row in data1.iterrows():
     # fetch the url as a file type object, then read the image
     f = urllib.request.urlopen(row["url"])
     a = plt.imread(f)

     # find the column by taking the current index modulo 3
     col = index % 3
     # plot on relevant subplot
     axarr[col,curr_row].imshow(a)
     if col == 2:
         # we have finished the current row, so increment row counter
         curr_row += 1