What is raster cell values?
First raster content indicated level of detail, or spatial resolution usually depends on the size of the picture elements (pixels). Pixel must be small enough so that it can capture the required details; while the pixel has to be large enough so that it can improve the efficiency of computer storage and analysis. Grid can use a smaller cell size of features represented in the range of more elements, less elements or more details.
How to change cell values raster file size
using ArcGIS resampling function can achieve this function.
About resampling
usually there are three ways resampling
1. nearest neighbor distribution method
2. bilinear interpolation
3. cubic convolution
Data Management Tools -> Raster -> Raster Processing -> resampling
By default, the nearest neighbor distribution resampling technique. This is because it applies to discrete data and continuous data, and other types of re-sampling (bilinear interpolation and cubic convolution) is only applicable to continuous data. Use resampling technique is necessary
in detail with reference
https://desktop.arcgis.com/zh-cn/arcmap/latest/extensions/spatial-analyst/performing-analysis/cell-size-and-resampling-in-analysis .htm