How do I get rid of blank pages between indexes in E-PUBin

[Coolmeadow Kid]

Hi! I'm new here. I've written 6 books and edited the HTML using Calibre. I don't know HTML, so I have to figure out how it converts from DOCX and figure out how to manipulate it to get it to show what I want. Seems each of the six books have totally different HTML codes to do the same thing. Drives me nuts.
I have encountered in each book that it is broken into different indexes by Calibre when it converts from DOCX to E-PUB. Book 1 has 4 indexes and is about 128,000 words. Very manageable. Book 6 is about 138,000 words and has 48 indexes! I can copy and paste and get rid of some, but that's a hassle. Any way to prevent this? Any way within the program to clean it up?
This latest book also has multiple blank pages that show up on the viewer. After index 1, it goes from 156.6 to 162, all blank. Index 2 starts up on page 163. It ends on 234.6 and index 3 picks back up on 237. Each index break has varying blank pages afterwards. All of the headers on each index are the same, letter for letter. Do I need to copy and paste all the indexes into one and get rid of all the individual headers so the book flows properly?
I'm open to anything that works as long as I don't have to learn a computer language. I have enough difficulties working with my native one!
I apologize if this is the wrong place to ask this question. I appreciate any help you can give me in plain language. Jim.