Create your budget using google docs spreadsheets, or similar, and provide a link to access this file (uploading an excel file to dropbox and providing the share link would also work).
If we fund your proposal, we will transfer the amount in your budget to the account of the staff sponsor you have included in your application. Please discuss the practicalities of this with your sponsor in advance, and ask questions to the LISS admin team (liss-dtp@kcl.ac.uk).
This budget should have roughly the following structure:

CATERING: It is possible to make use of university catering services for events if you want to, but these are generally more expensive, and more restricted in what they can offer than buying the food, drinks and plates/cups/etc yourselves.
TRAVEL/ACCOM: It's usually easiest to simply give your invitees a budget and let them book their own travel and submit an expense claim, but it is also possible for university departments to purchase tickets and book rooms for speakers with sufficient notice. You'll need to coordinate this through the department where your staff sponsor is located, so discuss this with them before putting in the application.
GENERAL NOTE: Be as clear and precise about what you are asking for as possible, and check your maths. We may elect not to fund your proposal if the sums seem excesive or unclear.