Reclassify by layer will not work if you just provide a table as a class break. The tool requires a vector layer, and based on vector layer you can choose the minimum and maximum values.
By Providing just a table such CSV file, the minimum and maximum fields are not activated:
But if you provide vector layer, they will be activated:
So the idea is to classify a raster data based on a vector layer which enables you to select minimum an maximum fields from the attribute table.
If you want to use a table and you define the values by yourself as a break values, you need to use
Reclassify by table tool:
If you have many rasters, you can use
Execute as Batch Process although it will be tough work if you have hundreds of raster data.