Why does the emperor issue a proclamation regarding Gulliver?

The emperor issues a proclamation regarding Gulliver primarily to control the crowd of curious Lilliputians. After Gulliver is discovered and becomes the center of attention, the large number of citizens flocking to see him causes disruptions and chaos. The emperor seeks to manage the situation, ensuring that the admiring crowds do not hinder the order of the city and that normal life and duties of the Lilliputians continue smoothly. This action reflects the emperor's desire to maintain stability and public order in a time when the presence of such a large and foreign entity poses unique challenges to their society.

In the context of the other options, while promoting Gulliver as a national hero or limiting food supplies may seem plausible at first, they do not address the direct need for managing the immediate impact of his presence on the city. Preventing Lilliputians from abandoning their work may have been an intention, but the primary motive of the proclamation was to manage the overwhelming curiosity and crowd control, highlighting the challenges of dealing with an unexpected visitor on this grand scale.