I added an excel in an attribute table using join opperation; I added the csv excel into geodatabase using import table opperation. The joined fields appear into attribute table, but when I right-click on a feature, and click on attribute, the attributes fields on the right side appear greyed. For an other layer, the attribute fields for feature appear blacked. What can I do in order to make attribute fields for the first layer to appear blacked like in the second case?
That is happening to you simply because the fields that are gray are in the joined table and are not in the layer you are editing (e.g. they are not editable).
The only way they are going to be editable is to make them a part of the layer you are editing so the steps you need to take are ...
1) Export the data with the joined table as a new layer.
2) Edit the new layer that now includes the fields from the joined table.