RTF coding is arcane, especially for tables. Unless you are an RTF expert, your best bet might be to copy existing RTF code. Here are some ways to obtain RTF code for your macros:
Get code examples from DITA2Go
Generate RTF code with DITA2Go.
You can pretty-print RTF output from Word to mine for code (if you open a Word RTF file directly in a text editor, you see only unbroken lines of unreadable code):
The RTF pretty-printer, pprtf.exe, takes either one or two arguments:
pprtf ExampleFile.rtf NewFile.txt
If you omit the second argument, the output is a file of the same name as the RTF file, but with extension .txt.
Get code examples from DITA2Go
Another way to obtain RTF code is to create an example in DITA, run DITA2Go, and then copy/paste the resulting RTF code into your d2rtf.ini configuration file or into a macro library file. DITA2Go produces RTF output that is even more readable than the output from pprtf.exe.
Generate RTF code with DITA2Go
For paragraphs, you can use CodeStore to generate RTF code; see §37.3.5.2 Inserting code with the CodeStore property.