Combining Postage

[sday8708]

When buyers have won multiple items it will only allow up to 40 items to be processed together. How can I increase this number?  I am selling 35 mm slides 

[plum993]

Your pics in listings breach ebay picture policies due to "Text" across the pics,see the policy here,so best edit them. Picture policy | eBay

Your also need to upgrade to a Business seller on ebay as your clearly listing as one,to comply with ebay policies and the UK law Creating an eBay account | eBay

As for combining why not group and list some of the same type of items together to start with.

[ile136yz]

On 'Seller's Preferences'   -   Buyer's Management - Buyer's Requirements

The amount can be increased up to a quantity of 100 in an 8 day period. This setting may only work if set up before any purchases made.