Can't Populate Large Tables Through PhpMyAdmin

I'm having trouble woth Yahoo php hosting.
My client wants to move his websites from H-Sphere reseller company where (everything works fine) to YAHOO (he thinks that service and reliability will be much better?).
The problem is with 'products' table where are 15000 records.
Yahoo's phpMyAdmin times out if I try to upload sql/txt file (3.5 mg). I can insert smaller tables pasting script into SQL window - no problem with 4000 records)
I can't do anything with products table (15000 records).
I did not have this problem with our current hosting company.
Under the upload window it says that txt file can be up to 10 mb but mine is only 3.5 mb.