Accessing a single cell on same row

You could edit your tables on a spreadsheet instead of within WordPress and then import it as a .csv every time you make changes. For example, in cell A1 you could use the formula:
="[table-cell id=123 cell="&A2&" /]"

…to include the contents of cell A2 within cell A1. It sounds like you’re wanting multiple cell contents in one cell so you would just add an & and then the formula for the next cell:

="[table-cell id=123 cell="&A2&" /]"&"[table-cell id=123 cell="&A3&" /]"&"[table-cell id=123 cell="&A4&" /]"

This makes cell A1 contain the contents of A2, A3, and A4. Then when you add/delete rows in the spreadsheet (unlike in TablePress via WordPress), your shortcodes are automatically updated. Don’t forget to save your spreadsheet with the formulas as .xls or .ods because when you save a copy as .csv it doesn’t preserve the formulas. So you will have two copies: the one you edit with the formulas and the one you save over and import.