I want to align all these pictures at top of the paragraph area at a time and set equal horizontal gaps between each image. How this could be possible with LibreOffice Writer? But, it is not possible to select two or more images in writer. I am attracting attention of the experts.
If the images are identical you could one anchor as character, then use customized tab stops, then copy/paste the original image. So they could have identical gaps.
In some cases a table could be useful.
IMHO: no
Workaround
Create your picture arrangement in Draw.
You can select images there and assign/arrange them.
Then group everything and copy it into Writer.
Character spacing could be fast to set (one value for all images).
There could help the em quad space (" ", U+2001).
If you don’t want to anchor your images As character (which could create other problems), you can still anchor them To paragraph in the same paragraph, by applying the same frame style.
However, this frame style must be correctly configured with Allow overlap unticked. Adjust horizontal spacing to your need.
Horizontal positioning should be set to left paragraph limit so that “conflicting” frames are offset on the right.
MOST IMPORTANT: refrain from moving the frames with the mouse. ANY infinitesimal suspicion of direct formatting will disable automatic repositioning.
So, if you’re not familiar and at ease with frame styles (the most difficult feature to master in Writer), follow @Grantler’s suggestion to anchor As character. But create a character style for spacing your images apart. This will make tuning easier than individual manual adjustment (see @LeroyG’s comment).