The answer depends on a lot of missing information, parenting styles being perhaps the most important (this has been borne out in many papers.) It's clear that you have a gentle and respectful approach to your child's rearing, which is very admirable and not as common in the US as the more authoritative/authoritarian approaches*. The question I would ask myself in your shoes, though, is which is more important, social issues or nutritional issues? If nutritional issues are most important, go with the separate table approach. But if you want your (completely appropriately) "picky" child to eat at the table with you later on, go with the table approach.
Nutrition is likely more of a focus in your country than in my obesity-prone one. Obesity in my country, however, is often an economic issue, so I'll assume there's no economic issue at play here.
Nutritionally, it is important to expose, and encourage your child to/towards lower caloric, healthier foods. Exposure is more than putting it in front of your child; while that is important, so is setting an example through what you eat. Children are genetically predisposed to sweet and salty foods, which is especially evident in 2-3 year olds. However, calorie dense foods are unnecessary in this group as their levels of physical activity does not require it. Avoidance of bitterness is also genetically determined in this age group, your child is behaving pretty much exactly as expected, so this is a given, whether at your table or not. So, what matters more?
You can't set a good example of healthy eating behavior if your child isn't at the table with you when you eat. One study showed that a rejected food is much more likely to be accepted after being offered eight times. Sitting with you at the table and continuing to offer these foods in the mix is doubly reinforcing healthy eating behavior later on, even if the child rejects them. Encouragement is gentle; anxiousness or forcing the child to eat is correlated with food-related issues later on.
I'm not sure that, in the presence of parents who (and a culture that) value and model healthy eating,, exactly what the child eats is as important as you might think. You'll find papers in the literature that are all over the place about this, so I'm basing my recommendation on what I've observed myself: early pickiness is normal, and most kids outgrow it, especially by the time adulthood rolls around.
The merits of offering (and accepting) different foods at a separate table are (imo) less convincing, but again, consider the source. Nutritionally, it's great, but not perfectly predictable of health and good eating habits. And while I sincerely admire the respect you're showing your child by this behavior, I'm not sure it's encouraging much pro-social behavior.
I would recommend the at-the-dinner-table approach, even at the expense of your concern for nutrition. Offer and eat healthy/nutritional foods yourself, but let the child eat enough of his favorites that he's not grumpy. I would also not rule out occasional bribery (e.g. offering a sticker chart with his favorite stickers, one per bite of rejected food, with a reward in full view to be dispensed after low-number-x bites of previously rejected food, e.g. a small toy.) I did this with my children, who loved inexpensive toys. It gave them pleasure and (?) a feeling of agency to obtain the toy, and it gave me pleasure to give it to them and see their happiness. No needless fussing if consistency is maintained.
*Just so you know where this answer is coming from, my approach was a mix of authoritative with a light helping of gentle. It's interesting that many papers coming out of Western countries don't even mention the more gentle approaches, settling on only authoritarian, authoritative, permissive and "neglectful".
Early Taste Experiences and Later Food Choices
Nurturing Children's Healthy Eating: Position statement