what does it tell you about gulliver when he disguises his own country and let it be own that he is a hollander?

From this, we can infer that Gulliver knew his survival techniques...... he wanted to go to Japan...... thus he had to claim himself a Dutchman, as the English were not welcome there.

I gave him a short account of some particulars, and made my story as plausible and consistent as I could; but I thought it necessary to disguise my country, and call myself a Hollander; because my intentions were for Japan, and I knew the Dutch were the only Europeans permitted to enter into that kingdom. I therefore told the officer, "that having been shipwrecked on the coast of Balnibarbi, and cast on a rock, I was received up into Laputa, or the flying island (of which he had often heard), and was now endeavouring to get to Japan, whence I might find a convenience of returning to my own country."