The Blob Memo view is the default view of the Blob Editor if the contents' format can not be determined, i.e. if it can not be determined if your data is of a supported picture format. You have full editing capabilities in this view, meaning copy, pasting and deleting. But this view also has a couple of nice to have features making your life easier and more productive.
For example, you can paste a URL into the editor, select it and then right click (or use the drop down text menu) to click "Download URL". The Blob Editor will then proceed to download the contents of the URL into your blob field, be it text, html or maybe a picture. If the column type is not a BLOB/MEMO then the column contents will be replaced with a link to the local downloaded file on your computer. In the same way you may also browse to any URL or even click "Send Email" to have your blob contents become your email message's body opened in your default email program. Of course you can load any contents from any file into your blob at any time, as well as save out your blob contents to any file of any type at any time. Pressing the usual keys like Ctrl+C (Copy), Ctrl+V (Paste), Ctrl+X (Cut) will result in your normal interactions with the clipboard and pressing Ctrl+Del will clear the current record's column blob's contents, i.e. resulting in it becoming a MySQL NULL value.