Page load time is a negative factor in Google's determination of page quality, which affects the page's ranking (see, for example, here). A very large page will therefore get proportionately penalized (quite good from my point of view as a user, because the page will load too slowly for me just as it does for Google's crawler).
As Alex said, page load time is an important factor. However, the page size is another important factor. You've mentioned about 70 images. I believe, search engines don't weigh images. The page size doesnt include images, when robots access them. They just see your ALT descriptions instead of images. So, you just need to weigh the page without images(still, the text description present in the ALT tag counts) and other graphical contents.
To answer your major question, the size of the file. Size is not a factor to avoid/select to search engines. But it does have a priority. They do prefer smaller files. So an optimum size for a page can be one which doesn't exceed 100K. This varies often based on the site objective and other needs.
But, my suggestion would be focus on the users than SEO. Even search engines say that. If the content will be useful for the customers, then you can always compramise SEO. Never SEO alone makes a site successful. Its good content which gets traffic.