Robert,
We will get this sorted out together...
Originally, I assumed you were symbolizing the landuse raster using Unique Value rendering and thus the zonal histogram table's label field would have the unique values for the raster in that column and require joining the zonal output table back to the input value raster table where Label = Value to establish/retain the landuse descriptions. I found that if you symbolize by Unique Values, but use the description field for the value field (on symbology tab) rather than the Value field, when you run Zonal Histogram the label field will automatically contain the descriptions your looking for so no further join is required. Please see screenshot-1 of result I obtained with this method.
Based on the table you sent and lack of label field, I do not believe you are using the Unique Value renderer. My example case is simple with only 7 landuse categories so ArcMap automatically uses Unique Value, but if your data has more than 26 unique values (and it does) then ArcMap will display it with a stretched renderer. If you leave it as stretched, AND your inputting a raster layer (rather than a raster dataset) then the layer's symbology defines the number of classes. When it's stretched you get 256 classes so most of your landuse will be zero's for each county. Hopefully this second screenshot helps clarify what is happening. The table on the left is Zonal Histogram with the Unique Value renderer and the table on the right is with Stretched. What you see is that the value 7 was stretched to 256 - county 1 still has 447 pixels of wetlands and county 2 has zero, but clearly using stretched is not the way to run this tool since the values for each landuse are stretched to the full 8 bit range and aren't really meaningful in terms of properly being able to join it back to get descriptions. This is how you got cotton growing in Ohio! The stretched value was joined, not the real value. 😄
To summarize:
1. Use the Unique Value renderer on the landuse raster.
2. On the symbology tab, set the value field to the landuse description field like in screenshot-3. My description field just happens to be called Landuse.
3. Run Zonal Histogram.
This should produce what you're looking for without further joins.
Best,
Eric