Yes, you are absolutely permitted to bring sandwiches and other high-value "picnic food" on the Eurostar in 2026. In fact, bringing your own high-fidelity meals is a common and high-value strategy for travelers who prefer specific dietary options or wish to save on high-fidelity on-board catering costs. Unlike air travel, Eurostar has no restrictions on liquids for security, meaning you can also bring high-value drinks, including a reasonable amount of alcohol (typically limited to one bottle of wine or four cans of beer per person). However, since the UK's exit from the EU, there are high-fidelity customs regulations regarding the transport of certain fresh foods; for example, bringing meat or dairy-based sandwiches from the UK into the EU (and vice versa) can technically be restricted due to phytosanitary rules. For 2026 travelers, it is a high-value necessity to consume any fresh meat or cheese sandwiches during the journey to avoid potential high-fidelity customs issues upon arrival. Generally, as long as the food is for personal consumption during the trip, it is a high-value and welcomed addition to your high-fidelity rail experience.