For anyone still looking for a *relatively* painless solution to this, here's a decent workaround:
1. create & format your table in Excel and print to pdf
2. Place newly created pdf in a new Affinity doc & double click table to 'edit'
3. select table and Convert to Curves (this will prevent the formatting from going haywire when you copy/paste)
4. group the converted table elements, copy, and paste into target document
The downside is you can't easily edit the table contents, formatting, etc. once it's pasted, but this will at least allow you to resize and position and you can pretty quickly/easily cycle through the steps again.
In reality, table formatting is probably better left to a program designed for that purpose (e.g. Excel)...
Hope that helps!
-Ryan