Don't worry as long as he is gaining weight and is acting normally. The transition to table foods can take longer for some kids. Some children are very sensitive to the different textures and consistencies. I had one child who spent a couple of months just sort of putting food in his mouth, rolling it around and then spitting it out without swallowing. He really seemed to just not like the way the table food felt in his mouth. My other son would probably have taken my arm off if I didn't shovel the food at him. He ate everything.
Just keep offering a variety of foods, and be a little creative. Remember that in other parts of the world, babies enjoy fish and seaweed. LOL Americans tend to feed babies bland, mushy foods. My family were immigrants, so I grew up eating a Mediterranean diet and enjoyed lots of fish and veggies from a very early age. When I gave my toddlers things like eggplant and poached fish, my mother-in-law almost went insane, but my kids happened to like it. Also, you might try making your own baby food rather than commercially processed food. They really tend to be so blah. Just whirl some yummy, healthy food in your blender or food processor, and see how your little one likes it. I did that a lot, and my picky eater much preferred the fresher food, though I did use jarred baby food, as well.