Try TorchSoft ASCII Art Studio
works on Windows
supports shapes, tables
text mode for easy editing
conversion from picture to ASCII
it has a 30 day trial
single user license is 29.95 $
The browser Browsh suggested by user simhumileco looks OK but the images are very low resolution.
Other suggestions are:
Lynx can be configured to display images using aaview or cacaview.
w3m can be configured to display images using cacaview.
Aaview can produce images as good as this:
Cacaview adds color, and can produce images as good as this:
Plain Text Table suits most of your requirements. It's free and open sourced
Use the tool online
Please visit : http://plaintexttools.github.io/plain-text-table
Interactive input table (using handsontable)
Unicode or ASCII output
Flexible border configuration
Merged cell support (colspan and rowspan)
Multiline text in the cells
Text alignement ...
What you show in your example looks a lot like UML.
If sequence diagrams are what you need, here's a tool that does both ASCII and Unicode
PlantUML, Open Source
For Android, I can warmly recommend Moon+ Reader Pro (for PDF, you will need the paid version). (One of) the fastest PDF readers, well supported – I use it myself for years. As a side-effect, you'll have the same features for many other eBook formats.
Annotations (and highlights) are saved into the PDF file directly (so you see them with other readers as ...