Impossible to add a block to Columns without also adding a Paragraph block, using the Inserter menu

[maddisondesigns]

Issue Overview

I wanted to add a Columns block with multiple images. When I insert a Columns block, it automatically adds a paragraph block, which I don't want. When I then use the Inserter menu to insert my Image block, I'm still left with a Paragraph block which I neither inserted or wanted!

If I use the Slash Command in the paragraph block, it converts to an Image block, but that's not good enough. Very few people are going to use the Slash Command. Unless you're used to using keyboard commands, most users are going to use the Inserter Menu. Using the Inserter menu though, it's impossible to add a columns block with just the blocks that I want. I'm always left with an extra Paragraph block, forcing me to have to delete something that I never even inserted in the first place!

Steps to Reproduce (for bugs)

1. Insert Columns Block
2. Using the Inserter menu, insert an Image block
3. Note that the Columns block now also contains a Paragraph block which I neither inserted or wanted

Expected Behavior

I expect to be able to add just the blocks that I want. Columns should not default to adding random blocks which I dont want

Current Behavior

Columns Block adds unwanted blocks when inserted

Firefox Quantum 58.0.2 (64-bit)
Gutenberg 2.2.0
WP 4.9.4