Desk Causing Comb Filtering

I'm not surprised to see this. Try to make a rockwool table - why not? Never heard of anyone doing it but maybe it's a profitable niche. The thing is, you're going to cover up most of it anyway. Why not just cover whatever area you can or just put the panel on your desk flat? You're up around 900Hz so even a 2" panel, forgive my lack of metric fluency, should do the trick. As far as a comfortable surface, maybe you can find some of that acoustically transparent film projector stuff and pull it really taught over some metal bars. Curious to see how you work this out.

With minimal equipment why not get rid of the table, put the speakers on stands and design a smaller working suface, like one of those old hospital bed trays on wheels also height adjustable, Or glueing some thin carpet similar that used in cars to your table top, but guessing that if hexspa is talking 2" rockwool then the carpet wouldnt suffice, im going to be building myself a work desk soon and was planning on covering the outside with a thin layer of carpet, but not the work surface, so keeping my eys open for any desk tips.

I think the key is to get the speakers off the table and put them farther back on stands, like this drawing from my Audio Expert book:

Along the lines of what pingpangpong said about a smaller table, what about NO table and just put your laptop and keyboard on stands.

Good point. I moved the microphone to different locations in the room, and it seems that the bass response from 35 to 300 hz is the best around 38 percent

Here are my $0.02. Feel free to ignore:

Without being in the room it's difficult for me to say but I think you're simply dealing with a specular desk reflection. Drilling big holes in your desk does not seem to be the best route forward. 
A great many recording and mixing rooms have desk/console reflections of some kind, so it's not the end of the world simply because great mixes are done every day in rooms with 'damaging' ER. 

Remember that we're dealing primarily with a time domain issue, which is CAUSING the frequency response issue you're showing, but the reference mic is omni and has no localization mechanism - it doesn't know the difference between that response created by a summation with an off-axis reflection, and that same response created by a lousy speaker under anechoic conditions. Our ears are a little better at this and can tell the difference between these two situations every time. Excellent data on this in Dr. Floyd E Toole's book "Sound Reproduction." Dr. Toole was one of the technical consultants on Ethan's book.

It's important to use your ears, not your eyes, with this type of thing because our brain has some very very powerful auditory processing abilities. For example, go stand in your bathroom with a friend and have them talk while you record it on your phone. Then play the recording back with headphones. It sounds like there's WAY more reverb on the recording, but there's not. Your brain is just very good at interpreting the arrivals from the walls and ignoring them / integrating them into the source sound. Same thing happens all the time using a reference mic in a live performance space. There will always be seatback reflections and floor reflections and rear-wall reflections and they show up on the measurements but everything sounds just fine in the room because your brain is smart enough to process all those reflections. So we learn how to spot them on the analyzer (phase response helps with this, too) because we don't want to try to equalize something that's not a problem to begin with. This is a major area where "auto EQ" fails, by the way. Every single person in every single seat is going to hear the "sit dip effect" and the seatback reflections and so on, so it's a completely normal part of what sounds normal to us. It's like EQing to "fix" the equal loudness contours, or the 3k boost in the human ear canal. It's a natural part of how our hearing works. Messing with it creates an unnatural sound.

I don't know if your desk reflection falls into that category or not, but I would say: how does it sound? Listen to some recordings you know very well, and if they sound good, leave it alone. If you legitimately hear a problem, then you can start worry about how to fix it.

Have you thought about simply using EQ?

www.prosoundtraining.com/2018/06/27/can-a-reflection-be-equalized/

Unless, you block your other ear. Then you usually hear that reverb "live" too. (A good way to check how your recordings will sound). In my apartment the reverb is pretty horrible, but to notice it i need to block my other ear. OR if i've been the whole day in the studio (not lots of verb + critical listening whole day) I notice the reverb.