Now The problem arises is that, the size of exported file "G1.eps" is very high. Near about 10 MB.
In such situation the best what can be done is to rasterize only the plot itself, keeping axes and labels in vector form. This problem was investigated for the first time by StackOverfow participant jmlopez and me in the thread "Rasters in 3D graphics." A solution for Mathematica 7 was developed. The proposed approach was further developed by Mathematica.SE participant halirutan in this answer. Note the huge number of upvotes: this functionality is highly appreciated by the community!
okie... thanks
EPS is a notoriously large format, and there's no point using it for this because ListPlot3Ds can't be exported as vector graphics anyways. Try a raster format like Export["G1.png", Graph1] or Export["G1.jpg", Graph1].
Export["G1.png", Graph1]
Export["G1.jpg", Graph1]
